Internet is the world largest computer network based on TCP/IP. That is, it is a network of networks that consists of millions of private, public, academic, business, and government networks. Internet share common mechanism for addressing (identifying) computers and common set of communication protocols for communication between the computers in the network. It is the widely used research tool, providing society with access to global information and instant communication. Internet addressing is used to identify each device, host, interface and resources in the internet. Common addressing technique used in Internet are IP address, Domain Name, URL.
The Internet carries different information resources and services, such as email, file transfer, news, online chat, remote login, online gaming and resources of WWW. Nowadays, Internet is the fastest and cheapest means to get, provide and compile information.
Internet is based on a client/server technology because most services that are accessed via the Internet work on the client/server model. In Internet, we have a server which provides a service, while clients connect to the server to make requests regarding the service. For example, In internet there are web servers and web client. Web browser(web client), using which we can request web pages and then the web servers accept the request and process it, send back the http response to client. Hence, the Internet is huge collection of server that responds to various types of clients.
Among the many services of Internet, WWW is the major service. The World Wide Web is an architectural framework for accessing interlinked hypertext documents spread out over millions of computers all over the internet. It is the system of interlinked hypertext documents accessed via the internet with the web browser. A user views web pages that may contain text, images, videos etc. and navigate between them using hyperlinks. WWW uses the concept of hypertext and hypermedia. In hypertext environment information is stored in a set of documents that are linked together. Hypertext document is document containing links to other pages and are created by using HTML. But the hypermedia document can contain pictures, graphics, animation and sound. WWW is based on HTTP. The WWW and HTTP :
- Allow you to create links from one pieces of information to another.
- Can incorporate references to sounds, graphics, movies
- Communicate with other internet protocol such as ftp, telnet, etc
The WWW uses a client/server model and HTTP for interaction between the computers in the internet. Any computer in the internet which uses the http protocol, called web server and any computer which can access the web server is called a web client. The web client makes the request to web server for a web pages through web browsers running the client machine and the web server running in the server machine sends back the requested pages. WWW is non linear, i.e, there is no top and no bottom and there is no start and no end. Thus in web :
- You can jump from one link to another.
- You can directly go to a resource if you know the URL. i.e, address
- You can jump to specific part of document.
There are various technologies that are used in developing and communication of web pages. Some front end technologies includes : HTML, CSS, JavaScript. Some of back-end includes : PHP, JAVA, Python, RUBY etc.
