World Wide Web

Networked computers are not new for us. We have been connecting computers in a LAN and WAN before Web. Even Web is a specialized version of what is called a client-server network. Client-server networks conserve computing resources by delegating complex and time-consuming computation to powerful, expensive computers called servers. Server machines tend to have large storage and memory capacity and multiple fast processors. Their speed allows them to complete computationally intense processing faster than a typical computer and then serve their results to smaller and less powerful machineswhich are known as clients.

In client-server networks, there are really three things of importance:

1. The server computer
2. One or more client computers
3. A connection between the client and server which is called as Network

At the client, a software must be developed to connect to the network to send and receive requests and data. It's the same for the server. At the network layer, we need protocols to allow the computers to communicate.
We alos need to handle bandwidth issues, lossy transmission of data, collisions, errors, and one or the other computer not being available.But all of this has been figured out for various situations. Protocols like Transmission Control Protocol (TCP), and User Datagram Protocol (UDP) as well as supporting protocols like Internet Protocol (IP), Address Resolution Protocol (ARP), and the Domain Name System (DNS) have been implemented and made easy to use for developers on both the client and server side.

World Wide Web: new network layer protocols, new server software to handle the connections and serve the variety of content demanded by the clients, and new client software to browse remote servers and search through the entire universe of servers for the one that had the required information. World Wide Web arrived as a network of computers that span over whole world and speak the same languages and protocols:

HyperText Transfer Protocol (HTTP),
Hypertext Markup Language (HTML),
eXtensible Markup Language (XML) etc.

The Web began largely as a replacement for the major functionality of the Internet: e-mail and File Transfer Protocol (FTP): ways of communicating and sharing files. Initially there was a method for sharing files between many users was a system called gopher. It was much like the Web we know today. GOPHER allowed users to search for documents using Veronica (the Google of its time) and documents could be linked together and navigated to.Gopher disapeared around 90s.HTML as a language of the Web was much more powerful and expressive than that used by gopher.

The magic behind this was a server-side program called a Web server that allowed remote clients to access certain parts of the server computer's hard drive. The Web changed everything about the way we shared files and communicated information.Web browser was the ultimate tool for a client computer to connect to the growing number of Web pages that were sprouting up on servers everywhere.

After that lot many things came into light for making this more dynamic in nature and flexible in usability.
These days many of us can't imagine life withoout these applicatons of World Wide Web...