Every retrievable piece of information on the Web is identified by a URL , which includes the name of the object, where it is located, and the protocol used to get it. T he Web server is responsible for document storage and retrieval. T he client interprets and presents the document. The client is responsible for document presentation. All Web clients and servers must be able to speak HTTP in order to send and receive hypermedia documents.
T here are many different Web servers, running on many platforms.