When people type URLs into their browsers, they are requesting information from the server. The server responds by downloading the page.
As we mentioned before, a Web site cannot be seen by others unless it is published to a Web server. What is a Web server?
A Web server is a computer that runs special serving software. That software "serves" HTML pages and associated files when requested by a client, such as a Web browser.
At first, when hearing the words "client" and "server," you might think you are at a restaurant. Well, this analogy is not that far off.
When you use your browser to visit a site, you typically make your request by entering a URL (for example: http://example.microsoft.com). A URL is a Uniform Resource Locator. It's simply an address for a file on the Web.
When the server receives your request, it serves or downloads the page you need, plus all of its associated files like pictures, and so on.