What is a web server?

A web server is a computer program that delivers (serves) content, such as this web page, using the Hypertext Transfer Protocol. The term web server can also refer to the computer or virtual machine running the program.

The primary function of a web server is to deliver web pages to clients (i.e. web browsers). This means delivery of HTML documents and any additional content that may be included by a document, such as images, style sheets and JavaScripts. While the primary function is to serve content, a full implementation of a web server also includes a way of receiving content from clients. This feature is used for submitting web forms, including uploading of files.

Examples of web servers include the Apache HTTP Server and Microsoft's Internet Information Services (IIS).