11.1 The World Wide Web

The World Wide Web (WWW or, simply, the web) is a distributed system of documents linked through hyperlinks and hosted on web servers across the Internet. In this section, we explain how the web works and describe the technologies that it relies on. We make use of these technologies in the web-based applications we develop in this chapter.

Web Servers and Web Clients

As mentioned earlier, the Internet is a global network that connects computers around the world. It allows programs running on two computers to send messages to each other. Typically, the communication occurs because one of the programs is requesting a resource (a file, say) from the other. The program that is the provider of the resource is referred to as a server. (The computer hosting the server program is often referred to as a server too.) The program requesting the resource is referred to as a client.