Wikipedia
world wide web (www) is a system of intelinked hypertext documents accessed via the internet
How the Web Works?
 |
| web working |
With a Web browser, a user views Web pages that may contain text, images,videos, and other multimedia and navigates between them using hyperlinks
The Major Components of Web
Networks
The local-area and wide-area networks connecting computers world-wide forming the Internet.
Clients
Web browsers that enable end-users to access the Web.
Servers
Constantly running programs that serve up information to the Web.
Documents
Web pages, mostly coded in HTML, that supply information on the Web.
Protocols
The Hyper Text Transfer Protocol HTTP that Web clients and servers use to talk to one another and the TCP/IP (Transmission Control Protocol) on which HTTP depends.
History of world wide web
§ In 1980
§ Tim Berners-Lee built ENQUIRE
§ personal database of people and software models,
§ each new page of information in ENQUIRE had to be linked to an existing page
§ In March 1989
§ Tim Berners-Lee wrote a proposal
§ referenced ENQUIRE and described a more elaborate information management system
§ In November 1990
§ Tim Berners-Lee publish a formal proposal with Robert Cailliau
§ In December 1990
§ Tim Berners-Lee built all the tools necessary for a working Web
§ the first Web browser (which was a Web editor as well),
§ the first Web server,
§ the first Web pages which described the project itself
§ In August 1991
§ Tim Berners-Lee posted a short summary of the World Wide Web project on the alt.hypertext newsgroup
§ On April 1993
§ CERN announced that the World Wide Web would be free to anyone
§ In 1993
§ introduction of the Mosaic Web browser
§ a graphical browser developed by a team at the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign (NCSA-UIUC)
§ In October 1994
§ Tim Berners-Lee found the World Wide Web Consortium (W3C)
 |
| www 1st |
Mozaic web browser
 |
| mosaic web browser |
Technology that Support the
World Wide Web
URL
§ The Web uses Uniform Resource Locators (URLs) to identify (locate)
resources (files and services) available on the Internet.
§ A URL may identify a host, a server port, and the target file stored on
that host
§ Format
§ scheme://server:port/pathname
DNS
§ DNS (Domain Name System)
§ The domain name system (DNS) provides a distributed database service that
supports dynamic update and retrieval of information contained in the name
space
 |
| dns |
HTTP
§ Hyper-text Transfer Protocol
§ Protocol that used for browser-server communication
§ Transaction framework
1.
Connection:
A browser (client) opens a connection to a server.
2.
Query: The
client requests a resource controlled by the server.
3.
Processing:
The server receives and processes the request.
4.
Response:
The server sends the requested resource back to the client.
5.
Termination:
The transaction is done and the connection is closed unless another transaction
will take place immediately between the client and server.
HTTP Query and Response
Formats
 |
| http query |
Hyper-text Transfer Protocol
 |
| http way |
The Future of World Wide Web
Web 2.0
§ Tim O'Reilly
§ "Web 2.0 is the business revolution in the computer industry caused by
the move to the Internet as platform, and an attempt to understand the rules for
success on that new platform"
§ Characteristics
§ “network as platform"
§ delivering (and allowing users to use) applications entirely through a
browser
§ users owning the data on the site and exercising control over that data
§ Characteristics
§ an architecture of participation and democracy that encourages users to add
value to the application as they use it
§ this stands in sharp contrast to hierarchical access control in
applications, in which systems categorize users into roles with varying levels
of functionality
§ a rich, interactive, user-friendly interface based on Ajax or similar
frameworks
§ some social-networking aspects
§ Technology
§ The complex and evolving technology infrastructure of Web 2.0 includes
§ server-software,
§ content-syndication,
§ messaging-protocols,
§ standards-based browsers with plugins and extensions,
§ and various client-applications
§ Features
§ A Web 2.0 website may typically feature a number of the following
techniques
§ Rich Internet application techniques, optionally Ajax-based
§ CSS
§ Semantically valid XHTML markup and the use of Microformats
§ Syndication and aggregation of data in RSS/Atom
§ Clean and meaningful URLs
§ Extensive use of folksonomies (in the form of tags or tagclouds, for
example)
§ Features
§ A Web 2.0 website may typically feature a number of the following
techniques
§ Use of wiki software either completely or partially (where partial use may
grow to become the complete platform for the site)
§ Use of Open source software either completely or partially, such as the
LAMP solution stack
§ Weblog publishing
§ Mashups
§ REST or XML Webservice APIs
Web 2.0 Examples
 |
| web 2.0 examples |
Application on The Web
 |
| web aplication |
0 comments
Post a Comment