UNIT- I
World Wide Web
The World Wide Web is a system of interlinked hypertext documents accessed via the Internet. With a Web browser, one can view Web pages that may contain text, images, videos, and other multimedia and navigate between them using hyperlinks. Using concepts from earlier hypertext systems, the World Wide Web was started in 1989 by the English physicist Sir Tim Berners-Lee, now the Director of the World Wide Web Consortium, and later by Robert Cailliau, a Belgian computer scientist, while both were working at CERN in Geneva, Switzerland. .
The World Wide Web enabled the spread of information over the Internet through an easy-to-use and flexible format. It thus played an important role in popularizing use of the Internet. Although the two terms are sometimes conflated in popular use, World Wide Web is not synonymous with Internet. The Web is an application built on top of the Internet.
How it works
“The terms Internet and World Wide Web are often used in every-day speech without much distinction. However, the Internet and the World Wide Web are not one and the same. The Internet is a global data communications system. It is a hardware and software infrastructure that provides connectivity between computers. In contrast, the Web is one of the services communicated via the Internet. It is a collection of interconnected documents and other resources, linked by hyperlinks and URLs. In short, the Web is an application running on the Internet.”
Viewing a Web page on the World Wide Web normally begins either by typing the URL of the page into a Web browser, or by following a hyperlink to that page or resource. The Web browser then initiates a series of communication messages, behind the scenes, in order to fetch and display it.
First, the server-name portion of the URL is resolved into an IP address using the global, distributed Internet database known as the domain name system, or DNS. This IP address is necessary to contact the Web server. The browser then requests the resource by sending an HTTP request to the Web server at that particular address. In the case of a typical Web page, the HTML text of the page is requested first and parsed immediately by the Web browser, which then makes additional requests for images and any other files that form parts of the page. Statistics measuring a website's popularity are usually based either on the number of 'page views' or associated server 'hits' (file requests) that take place.
Having received the required files from the Web server, the browser then renders the page onto the screen as specified by its HTML, CSS, and other Web languages. Any images and other resources are incorporated to produce the on-screen Web page that the user sees.
Most Web pages will themselves contain hyperlinks to other related pages and perhaps to downloads, source documents, definitions and other Web resources. Such a collection of useful, related resources, interconnected via hypertext links, is what was dubbed a "web" of information. Making it available on the Internet created what Tim Berners-Lee first called the WorldWideWeb.
Standards:
Many formal standards and other technical specifications define the operation of different aspects of the World Wide Web, the Internet, and computer information exchange. Many of the documents are the work of the World Wide Web Consortium (W3C), headed by Berners-Lee, but some are produced by the Internet Engineering Task Force (IETF) and other organizations.
Usually, when Web standards are discussed, the following publications are seen as foundational:
Recommendations for markup languages, especially HTML and XHTML, from the W3C. These define the structure and interpretation of hypertext documents.
Recommendations for stylesheets, especially CSS, from the W3C.
Standards for ECMAScript (usually in the form of JavaScript), from Ecma International.
Recommendations for the Document Object Model, from W3C.
Additional publications provide definitions of other essential technologies for the World Wide Web, including, but not limited to, the following:
Uniform Resource Identifier (URI), which is a universal system for referencing resources on the Internet, such as hypertext documents and images. URIs, often called URLs, are defined by the IETF's RFC 3986
HyperText Transfer Protocol (HTTP), especially as defined by RFC 2616: HTTP/1.1 and RFC 2617: HTTP Authentication, which specify how the browser and server authenticate each other.
Web Protocols: Below is a list of protocols used for the world wide web.ARP: Address Resolution ProtocolDHCP: Dynamic Host Configuration ProtocolDNS: Domain Name ServiceDSN: Data Source NameFTP: File Transfer ProtocolHTTP: Hypertext Transfer ProtocolIMAP: Internet Message Access ProtocolICMP: Internet Control Message Protocol IP: Internet ProtocolIRC: Internet Relay Chat ProtocolSMTP: Simple Mail Transfer ProtocolSSL: Secure Sockets LayerTCP: Transmission Control ProtocolTELNET: TCP/IP Terminal Emulation ProtocolUPD: User Datagram Protocol
Protocols governing the web :
The TCP/IP suite of protocols is the set of protocols used to communicate across the internet. It is also widely used on many organizational networks due to its flexibility and wide array of functionality provided. TCP/IP is a set of protocols which is used to govern the web. The division of TCP/IP protocols layer wise and function wise is as follows: TCP/IP by Layer:
Link Layer
SLIP - Serial Line Internet Protocol. This protocol places data packets into data frames in preparation for transport across network hardware media. This protocol is used for sending data across serial lines. There is no error correction, addressing or packet identification. There is no authentication or negotiation capabilities with SLIP. SLIP will only support transport of IP packets.
CSLIP - Compressed SLIP is essentially data compression of the SLIP protocol. It uses Van Jacobson compression to drastically reduce the overhead of packet overhead. This may also be used with PPP and called CPPP.
PPP - Point to Point Protocol is a form of serial line data encapsulation that is an improvement over SLIP which provides serial bi-directional communication. It is much like SLIP but can support AppleTalk, IPX, TCP/IP, and NetBEUI along with TCP/IP which is supported by SLIP. It can negociate connection parameters such as speed along with the ability to support PAP and CHAP user authentication.
Ethernet - Ethernet is not really called a protocol. There are also many types of ethernet. The most common ethernet which is used to control the handling of data at the lowest layer of the network model is 802.3 ethernet. 802.3 ethernet privides a means of encapsulating data frames to be sent between computers. It specifies how network data collisions are handled along with hardware addressing of network cards.
Network Layer
ARP - Address Resolution Protocol enables the packaging of IP data into ethernet packages. It is the system and messaging protocol that is used to find the ethernet (hardware) address from a specific IP number. Without this protocol, the ethernet package could not be generated from the IP package, because the ethernet address could not be determined.
IP - Internet Protocol. Except for ARP and RARP all protocols' data packets will be packaged into an IP data packet. IP provides the mechanism to use software to address and manage data packets being sent to computers.
RARP - Reverse address resolution protocol is used to allow a computer without a local permanent data storage media to determine its IP address from its ethernet address.
Transport Layer
· TCP - A reliable connection oriented protocol used to control the management of application level services between computers. It is used for transport by some applications.
· UDP - An unreliable connection less protocol used to control the management of application level services between computers. It is used for transport by some applications which must provide their own reliability.
· ICMP - Internet control message protocol (ICMP) provides management and error reporting to help manage the process of sending data between computers. (Management). This protocol is used to report connection status back to computers that are trying to connect other computers. For example, it may report that a destination host is not reachable.
Application Layer
FTP - File Transfer Protocol allows file transfer between two computers with login required.
TFTP - Trivial File Transfer Protocol allows file transfer between two computers with no login required. It is limited, and is intended for diskless stations.
NFS - Network File System is a protocol that allows UNIX and Linux systems remotely mount each other's file systems.
SNMP - Simple Network Management Protocol is used to manage all types of network elements based on various data sent and received.
SMTP - Simple Mail Transfer Protocol is used to transport mail. Simple Mail Transport Protocol is used on the internet, it is not a transport layer protocol but is an application layer protocol.
HTTP - Hypertext Transfer Protocol is used to transport HTML pages from web servers to web browsers. The protocol used to communicate between web servers and web browser software clients.
BOOTP - Bootstrap protocol is used to assign an IP address to diskless computers and tell it what server and file to load which will provide it with an operating system.
DHCP - Dynamic host configuration protocol is a method of assigning and controlling the IP addresses of computers on a given network. It is a server based service that automatically assigns IP numbers when a computer boots. This way the IP address of a computer does not need to be assigned manually. This makes changing networks easier to manage. DHCP can perform all the functions of BOOTP.
RIP - Routing Information Protocol is used to dynamically update router tables on WANs or the internet. A distance-vector algorithm is used to calculate the best route for a packet.
POP3 - Post Office Protocol version 3 is used by clients to access an internet mail server to get mail. It is not a transport layer protocol.
IMAP4 - Internet Mail Access Protocol version 4 is the replacement for POP3.
Telnet is used to remotely open a session on another computer. It relies on TCP for transport and is defined by RFC854. .
Mail Protocols
SMTP - Simple Mail Transfer Protocol is used to transport mail. Simple Mail Transport Protocol is used on the internet, it is not a transport layer protocol but is an application layer protocol.
POP3 - Post Office Protocol version 3 is used by clients to access an internet mail server to get mail. It is not a transport layer protocol.
IMAP4 - Internet Mail Access Protocol version 4 is the replacement for POP3.
Multicasting Protocols
IGMP - Internet Group Management Protocol used to support multicasting. IGMP messages are used by multicast routers to track group memberships on each of its networks.
Website
A website (or web site) is a collection of related web pages, images, videos or other digital assets that are addressed with a common domain name or IP address in an Internet Protocol-based network. A web site is hosted on at least one web server, accessible via the Internet or a private local area network.
Before the introduction of HTML and HTTP other protocols such as file transfer protocol and the gopher protocol were used to retrieve individual files from a server. These protocols offer a simple directory structure which the user navigates and chooses files to download. Documents were most often presented as plain text files without formatting or were encoded in word processor formats.
Organized by function, a website may be
A personal website
A commercial website
A government website
A non-profit organization website
It could be the work of an individual, a business or other organization, and is typically dedicated to some particular topic or purpose. Any website can contain a hyperlink to any other website, so the distinction between individual sites, as perceived by the user, may sometimes be blurred.
Websites are written in, or dynamically converted to, HTML (Hyper Text Markup Language) and are accessed using a software interface classified as a user agent. Web pages can be viewed or otherwise accessed from a range of computer-based and Internet-enabled devices of various sizes, including desktop computers, laptops, PDAs and cell phones.
A website is hosted on a computer system known as a web server, also called an HTTP server, and these terms can also refer to the software that runs on these systems and that retrieves and delivers the web pages in response to requests from the website users. Apache is the most commonly used web server software (according to Netcraft statistics) and Microsoft's Internet Information Server (IIS) is also commonly used.
Website styles: Static website
A static website is one that has web pages stored on the server in the format that is sent to a client web browser. It is primarily coded in HTML.Simple forms or marketing examples of websites, such as classic website, a five-page website or a brochure website are often static websites, because they present pre-defined, static information to the user. This may include information about a company and its products and services via text, photos, Flash animation, audio/video and interactive menus and navigation.
This type of website usually displays the same information to all visitors. Similar to handing out a printed brochure to customers or clients, a static website will generally provide consistent, standard information for an extended period of time. Although the website owner may make updates periodically, it is a manual process to edit the text, photos and other content and may require basic website design skills and software.
In summary, visitors are not able to control what information they receive via a static website, and must instead settle for whatever content the website owner has decided to offer at that time.
Dynamic website
A dynamic website is one that changes or customizes content automatically and/or frequently based on certain criteria. The page composition is usually data-driven and collates information ad hoc each time a page is requested.
A website can be dynamic in one of two ways. The first is that the web page code is constructed dynamically. The second is that the web page content displayed varies based on certain criteria. The criteria may be pre-defined rules or may be based on variable user input.
The main purpose of a dynamic website is that it is much simpler to maintain a few template pages and a database than it is to build and update hundreds or thousands of individual web pages and links.
Software systems:
There are a wide range of software systems, such as Java Server Pages (JSP), the PHP and Perl programming languages, Active Server Pages (ASP), YUMA and Cold Fusion (CFM) that are available to generate dynamic web systems and dynamic sites. Sites may also include content that is retrieved from one or more databases or by using XML-based technologies such as RSS.
Static content may also be dynamically generated either periodically, or if certain conditions for regeneration occur (cached) in order to avoid the performance loss of initiating the dynamic engine on a per-user or per-connection basis.
Plug ins are available to expand the features and abilities of web browsers, which use them to show active content, such as Flash, Shockwave or applets written in Java. Dynamic HTML also provides for user interactivity and realtime element updating within web pages , mainly using the DOM and JavaScript, support which is built-in to most modern web browsers.
Types of websites
There are many varieties of websites, each specializing in a particular type of content or use, and they may be arbitrarily classified in any number of ways. A few such classifications might include:
Archive site: used to preserve valuable electronic content threatened with extinction. Two examples are: Internet Archive, which since 1996 has preserved billions of old (and new) web pages; and Google Groups, which in early 2005 was archiving over 845,000,000 messages posted to Usenet news/discussion groups.
Blog (or web log) site: sites generally used to post online diaries which may include discussion forums (e.g., blogger, Xanga).
Content site: sites whose business is the creation and distribution of original content (e.g., Slate, About.com).
Corporate website: used to provide background information about a business, organization, or service.
Electronic commerce (eCommerce) site: a site offering goods and services for online sale and enabling online transactions for such sales.
Community site: a site where persons with similar interests communicate with each other, usually by chat or message boards, such as MySpace or Facebook.
City Site: A site that shows information about a certain city or town and events that takes place in that town. Usually created by the city council or other "movers and shakers".
News site: similar to an information site, but dedicated to dispensing news and commentary.
Personal homepage: run by an individual or a small group (such as a family) that contains information or any content that the individual wishes to include. These are usually uploaded using a web hosting service such as Geocities.
Political site: A site on which people may voice political views.
Personal web page
Personal web pages are World Wide Web pages created by an individual to contain content of a personal nature. The content can be about that person or about something he or she is interested in. Personal web pages can be the entire content of a domain name belonging to the person (which would then be a personal website), or can be a page or pages that are part of a larger domain on which other pages are located - an example of one such larger site is GeoCities. Another example would be a student's website for school. Personal web pages are often used solely for informative or entertainment purposes. Defining personal web page is difficult, because many domains or combinations of web pages that are under the control of a single individual can be used by the individual for commercial purposes etc.
Personal web pages may be as simple as a single page or may be as elaborate as an online database with gigabytes of data. Many Internet service providers offer a few megabytes of space for customers to host their own personal web pages.
The content of personal web pages varies and can, depending on the hosting server, contain anything that any other websites do. However, typical personal web pages contain images, text and a collection of hyperlinks. Many can contain biographical information, résumés, and blogs. Many personal pages will include information about the author's hobbies and pastimes, and information of interest to friends and family of the author.
Corporate website
A corporate website or corporate site is an informational website operated by a business or other private enterprise such as a charity or nonprofit foundation.
Characteristics:
Corporate sites differ from electronic commerce, portal, or sites in that they provide information to the public about the company rather than transacting business or providing other services. The phrase is a term of art referring to the purpose of the site rather than its design or specific features, or the nature, market sector, or business structure of the site operator.
Nearly every company that interacts with the public has a corporate site or else integrates the same features into its other websites. Large companies typically maintain a single umbrella corporate site for all of their various brands and subsidiaries.
Common Features:
Corporate websites usually include the following:
A homepage
A navigation bar or other means for accessing various site sections
A unified look and feel incorporating the company logos, style sheets, and graphic images.
An "about us" section with some or all of these:
A summary of company operations, history, and mission statement
A list of the company's products and services
A "people" section with biographical information on founders, board members, and/or key executives. Sometimes provides an overview of the company's overall workforce.
A "news" section containing press releases, press kits, and/or links to news articles about the company
An "investor" section describing key owners / investors of the company
A list of key clients, suppliers, achievements, projects, partners, or others .
World Wide Web
The World Wide Web is a system of interlinked hypertext documents accessed via the Internet. With a Web browser, one can view Web pages that may contain text, images, videos, and other multimedia and navigate between them using hyperlinks. Using concepts from earlier hypertext systems, the World Wide Web was started in 1989 by the English physicist Sir Tim Berners-Lee, now the Director of the World Wide Web Consortium, and later by Robert Cailliau, a Belgian computer scientist, while both were working at CERN in Geneva, Switzerland. .
The World Wide Web enabled the spread of information over the Internet through an easy-to-use and flexible format. It thus played an important role in popularizing use of the Internet. Although the two terms are sometimes conflated in popular use, World Wide Web is not synonymous with Internet. The Web is an application built on top of the Internet.
How it works
“The terms Internet and World Wide Web are often used in every-day speech without much distinction. However, the Internet and the World Wide Web are not one and the same. The Internet is a global data communications system. It is a hardware and software infrastructure that provides connectivity between computers. In contrast, the Web is one of the services communicated via the Internet. It is a collection of interconnected documents and other resources, linked by hyperlinks and URLs. In short, the Web is an application running on the Internet.”
Viewing a Web page on the World Wide Web normally begins either by typing the URL of the page into a Web browser, or by following a hyperlink to that page or resource. The Web browser then initiates a series of communication messages, behind the scenes, in order to fetch and display it.
First, the server-name portion of the URL is resolved into an IP address using the global, distributed Internet database known as the domain name system, or DNS. This IP address is necessary to contact the Web server. The browser then requests the resource by sending an HTTP request to the Web server at that particular address. In the case of a typical Web page, the HTML text of the page is requested first and parsed immediately by the Web browser, which then makes additional requests for images and any other files that form parts of the page. Statistics measuring a website's popularity are usually based either on the number of 'page views' or associated server 'hits' (file requests) that take place.
Having received the required files from the Web server, the browser then renders the page onto the screen as specified by its HTML, CSS, and other Web languages. Any images and other resources are incorporated to produce the on-screen Web page that the user sees.
Most Web pages will themselves contain hyperlinks to other related pages and perhaps to downloads, source documents, definitions and other Web resources. Such a collection of useful, related resources, interconnected via hypertext links, is what was dubbed a "web" of information. Making it available on the Internet created what Tim Berners-Lee first called the WorldWideWeb.
Standards:
Many formal standards and other technical specifications define the operation of different aspects of the World Wide Web, the Internet, and computer information exchange. Many of the documents are the work of the World Wide Web Consortium (W3C), headed by Berners-Lee, but some are produced by the Internet Engineering Task Force (IETF) and other organizations.
Usually, when Web standards are discussed, the following publications are seen as foundational:
Recommendations for markup languages, especially HTML and XHTML, from the W3C. These define the structure and interpretation of hypertext documents.
Recommendations for stylesheets, especially CSS, from the W3C.
Standards for ECMAScript (usually in the form of JavaScript), from Ecma International.
Recommendations for the Document Object Model, from W3C.
Additional publications provide definitions of other essential technologies for the World Wide Web, including, but not limited to, the following:
Uniform Resource Identifier (URI), which is a universal system for referencing resources on the Internet, such as hypertext documents and images. URIs, often called URLs, are defined by the IETF's RFC 3986
HyperText Transfer Protocol (HTTP), especially as defined by RFC 2616: HTTP/1.1 and RFC 2617: HTTP Authentication, which specify how the browser and server authenticate each other.
Web Protocols: Below is a list of protocols used for the world wide web.ARP: Address Resolution ProtocolDHCP: Dynamic Host Configuration ProtocolDNS: Domain Name ServiceDSN: Data Source NameFTP: File Transfer ProtocolHTTP: Hypertext Transfer ProtocolIMAP: Internet Message Access ProtocolICMP: Internet Control Message Protocol IP: Internet ProtocolIRC: Internet Relay Chat ProtocolSMTP: Simple Mail Transfer ProtocolSSL: Secure Sockets LayerTCP: Transmission Control ProtocolTELNET: TCP/IP Terminal Emulation ProtocolUPD: User Datagram Protocol
Protocols governing the web :
The TCP/IP suite of protocols is the set of protocols used to communicate across the internet. It is also widely used on many organizational networks due to its flexibility and wide array of functionality provided. TCP/IP is a set of protocols which is used to govern the web. The division of TCP/IP protocols layer wise and function wise is as follows: TCP/IP by Layer:
Link Layer
SLIP - Serial Line Internet Protocol. This protocol places data packets into data frames in preparation for transport across network hardware media. This protocol is used for sending data across serial lines. There is no error correction, addressing or packet identification. There is no authentication or negotiation capabilities with SLIP. SLIP will only support transport of IP packets.
CSLIP - Compressed SLIP is essentially data compression of the SLIP protocol. It uses Van Jacobson compression to drastically reduce the overhead of packet overhead. This may also be used with PPP and called CPPP.
PPP - Point to Point Protocol is a form of serial line data encapsulation that is an improvement over SLIP which provides serial bi-directional communication. It is much like SLIP but can support AppleTalk, IPX, TCP/IP, and NetBEUI along with TCP/IP which is supported by SLIP. It can negociate connection parameters such as speed along with the ability to support PAP and CHAP user authentication.
Ethernet - Ethernet is not really called a protocol. There are also many types of ethernet. The most common ethernet which is used to control the handling of data at the lowest layer of the network model is 802.3 ethernet. 802.3 ethernet privides a means of encapsulating data frames to be sent between computers. It specifies how network data collisions are handled along with hardware addressing of network cards.
Network Layer
ARP - Address Resolution Protocol enables the packaging of IP data into ethernet packages. It is the system and messaging protocol that is used to find the ethernet (hardware) address from a specific IP number. Without this protocol, the ethernet package could not be generated from the IP package, because the ethernet address could not be determined.
IP - Internet Protocol. Except for ARP and RARP all protocols' data packets will be packaged into an IP data packet. IP provides the mechanism to use software to address and manage data packets being sent to computers.
RARP - Reverse address resolution protocol is used to allow a computer without a local permanent data storage media to determine its IP address from its ethernet address.
Transport Layer
· TCP - A reliable connection oriented protocol used to control the management of application level services between computers. It is used for transport by some applications.
· UDP - An unreliable connection less protocol used to control the management of application level services between computers. It is used for transport by some applications which must provide their own reliability.
· ICMP - Internet control message protocol (ICMP) provides management and error reporting to help manage the process of sending data between computers. (Management). This protocol is used to report connection status back to computers that are trying to connect other computers. For example, it may report that a destination host is not reachable.
Application Layer
FTP - File Transfer Protocol allows file transfer between two computers with login required.
TFTP - Trivial File Transfer Protocol allows file transfer between two computers with no login required. It is limited, and is intended for diskless stations.
NFS - Network File System is a protocol that allows UNIX and Linux systems remotely mount each other's file systems.
SNMP - Simple Network Management Protocol is used to manage all types of network elements based on various data sent and received.
SMTP - Simple Mail Transfer Protocol is used to transport mail. Simple Mail Transport Protocol is used on the internet, it is not a transport layer protocol but is an application layer protocol.
HTTP - Hypertext Transfer Protocol is used to transport HTML pages from web servers to web browsers. The protocol used to communicate between web servers and web browser software clients.
BOOTP - Bootstrap protocol is used to assign an IP address to diskless computers and tell it what server and file to load which will provide it with an operating system.
DHCP - Dynamic host configuration protocol is a method of assigning and controlling the IP addresses of computers on a given network. It is a server based service that automatically assigns IP numbers when a computer boots. This way the IP address of a computer does not need to be assigned manually. This makes changing networks easier to manage. DHCP can perform all the functions of BOOTP.
RIP - Routing Information Protocol is used to dynamically update router tables on WANs or the internet. A distance-vector algorithm is used to calculate the best route for a packet.
POP3 - Post Office Protocol version 3 is used by clients to access an internet mail server to get mail. It is not a transport layer protocol.
IMAP4 - Internet Mail Access Protocol version 4 is the replacement for POP3.
Telnet is used to remotely open a session on another computer. It relies on TCP for transport and is defined by RFC854. .
Mail Protocols
SMTP - Simple Mail Transfer Protocol is used to transport mail. Simple Mail Transport Protocol is used on the internet, it is not a transport layer protocol but is an application layer protocol.
POP3 - Post Office Protocol version 3 is used by clients to access an internet mail server to get mail. It is not a transport layer protocol.
IMAP4 - Internet Mail Access Protocol version 4 is the replacement for POP3.
Multicasting Protocols
IGMP - Internet Group Management Protocol used to support multicasting. IGMP messages are used by multicast routers to track group memberships on each of its networks.
Website
A website (or web site) is a collection of related web pages, images, videos or other digital assets that are addressed with a common domain name or IP address in an Internet Protocol-based network. A web site is hosted on at least one web server, accessible via the Internet or a private local area network.
Before the introduction of HTML and HTTP other protocols such as file transfer protocol and the gopher protocol were used to retrieve individual files from a server. These protocols offer a simple directory structure which the user navigates and chooses files to download. Documents were most often presented as plain text files without formatting or were encoded in word processor formats.
Organized by function, a website may be
A personal website
A commercial website
A government website
A non-profit organization website
It could be the work of an individual, a business or other organization, and is typically dedicated to some particular topic or purpose. Any website can contain a hyperlink to any other website, so the distinction between individual sites, as perceived by the user, may sometimes be blurred.
Websites are written in, or dynamically converted to, HTML (Hyper Text Markup Language) and are accessed using a software interface classified as a user agent. Web pages can be viewed or otherwise accessed from a range of computer-based and Internet-enabled devices of various sizes, including desktop computers, laptops, PDAs and cell phones.
A website is hosted on a computer system known as a web server, also called an HTTP server, and these terms can also refer to the software that runs on these systems and that retrieves and delivers the web pages in response to requests from the website users. Apache is the most commonly used web server software (according to Netcraft statistics) and Microsoft's Internet Information Server (IIS) is also commonly used.
Website styles: Static website
A static website is one that has web pages stored on the server in the format that is sent to a client web browser. It is primarily coded in HTML.Simple forms or marketing examples of websites, such as classic website, a five-page website or a brochure website are often static websites, because they present pre-defined, static information to the user. This may include information about a company and its products and services via text, photos, Flash animation, audio/video and interactive menus and navigation.
This type of website usually displays the same information to all visitors. Similar to handing out a printed brochure to customers or clients, a static website will generally provide consistent, standard information for an extended period of time. Although the website owner may make updates periodically, it is a manual process to edit the text, photos and other content and may require basic website design skills and software.
In summary, visitors are not able to control what information they receive via a static website, and must instead settle for whatever content the website owner has decided to offer at that time.
Dynamic website
A dynamic website is one that changes or customizes content automatically and/or frequently based on certain criteria. The page composition is usually data-driven and collates information ad hoc each time a page is requested.
A website can be dynamic in one of two ways. The first is that the web page code is constructed dynamically. The second is that the web page content displayed varies based on certain criteria. The criteria may be pre-defined rules or may be based on variable user input.
The main purpose of a dynamic website is that it is much simpler to maintain a few template pages and a database than it is to build and update hundreds or thousands of individual web pages and links.
Software systems:
There are a wide range of software systems, such as Java Server Pages (JSP), the PHP and Perl programming languages, Active Server Pages (ASP), YUMA and Cold Fusion (CFM) that are available to generate dynamic web systems and dynamic sites. Sites may also include content that is retrieved from one or more databases or by using XML-based technologies such as RSS.
Static content may also be dynamically generated either periodically, or if certain conditions for regeneration occur (cached) in order to avoid the performance loss of initiating the dynamic engine on a per-user or per-connection basis.
Plug ins are available to expand the features and abilities of web browsers, which use them to show active content, such as Flash, Shockwave or applets written in Java. Dynamic HTML also provides for user interactivity and realtime element updating within web pages , mainly using the DOM and JavaScript, support which is built-in to most modern web browsers.
Types of websites
There are many varieties of websites, each specializing in a particular type of content or use, and they may be arbitrarily classified in any number of ways. A few such classifications might include:
Archive site: used to preserve valuable electronic content threatened with extinction. Two examples are: Internet Archive, which since 1996 has preserved billions of old (and new) web pages; and Google Groups, which in early 2005 was archiving over 845,000,000 messages posted to Usenet news/discussion groups.
Blog (or web log) site: sites generally used to post online diaries which may include discussion forums (e.g., blogger, Xanga).
Content site: sites whose business is the creation and distribution of original content (e.g., Slate, About.com).
Corporate website: used to provide background information about a business, organization, or service.
Electronic commerce (eCommerce) site: a site offering goods and services for online sale and enabling online transactions for such sales.
Community site: a site where persons with similar interests communicate with each other, usually by chat or message boards, such as MySpace or Facebook.
City Site: A site that shows information about a certain city or town and events that takes place in that town. Usually created by the city council or other "movers and shakers".
News site: similar to an information site, but dedicated to dispensing news and commentary.
Personal homepage: run by an individual or a small group (such as a family) that contains information or any content that the individual wishes to include. These are usually uploaded using a web hosting service such as Geocities.
Political site: A site on which people may voice political views.
Personal web page
Personal web pages are World Wide Web pages created by an individual to contain content of a personal nature. The content can be about that person or about something he or she is interested in. Personal web pages can be the entire content of a domain name belonging to the person (which would then be a personal website), or can be a page or pages that are part of a larger domain on which other pages are located - an example of one such larger site is GeoCities. Another example would be a student's website for school. Personal web pages are often used solely for informative or entertainment purposes. Defining personal web page is difficult, because many domains or combinations of web pages that are under the control of a single individual can be used by the individual for commercial purposes etc.
Personal web pages may be as simple as a single page or may be as elaborate as an online database with gigabytes of data. Many Internet service providers offer a few megabytes of space for customers to host their own personal web pages.
The content of personal web pages varies and can, depending on the hosting server, contain anything that any other websites do. However, typical personal web pages contain images, text and a collection of hyperlinks. Many can contain biographical information, résumés, and blogs. Many personal pages will include information about the author's hobbies and pastimes, and information of interest to friends and family of the author.
Corporate website
A corporate website or corporate site is an informational website operated by a business or other private enterprise such as a charity or nonprofit foundation.
Characteristics:
Corporate sites differ from electronic commerce, portal, or sites in that they provide information to the public about the company rather than transacting business or providing other services. The phrase is a term of art referring to the purpose of the site rather than its design or specific features, or the nature, market sector, or business structure of the site operator.
Nearly every company that interacts with the public has a corporate site or else integrates the same features into its other websites. Large companies typically maintain a single umbrella corporate site for all of their various brands and subsidiaries.
Common Features:
Corporate websites usually include the following:
A homepage
A navigation bar or other means for accessing various site sections
A unified look and feel incorporating the company logos, style sheets, and graphic images.
An "about us" section with some or all of these:
A summary of company operations, history, and mission statement
A list of the company's products and services
A "people" section with biographical information on founders, board members, and/or key executives. Sometimes provides an overview of the company's overall workforce.
A "news" section containing press releases, press kits, and/or links to news articles about the company
An "investor" section describing key owners / investors of the company
A list of key clients, suppliers, achievements, projects, partners, or others .
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