This diagram shows the basic styles of interactions between users and a Web server.

This disgram shows a conceptual view of how a Web browser connects to a Web server, as well as how a user can privately interact with a Web server to transfer files and access services. Above the line, a user’s Web browser interacts with any Web server on the Web using a protocol called HTTP. The browser sends requests to the Web server, and it responds with HTML pages. Notice, though, that the Web server can call on many services besides its own hard drive. These other services actually create the HTML as it is requested, rather than using static pages that change rarely.

Below the line, however, a user with the proper permissions can connect to the private side of a Web server, and directly access the Web server’s hard drive and other services (such as MySQL databases).