A web server is an application that serves content such as web pages, images, video, and other files to clients over the World Wide Web. It serves requests from clients, typically web browsers, using the Hypertext Transfer Protocol (HTTP) and another language like PHP or ASP. The web server is the program responsible for accepting incoming requests to a website and responding to those requests with appropriate content.
The most commonly used web server today is Apache HTTP Server, which is open-source and highly customizable. Other web servers include Microsoft IIS, which is designed primarily for Windows systems, and the open-source Nginx web server. Web servers can also be used to host databases, and they are often used in tandem with application servers for delivering the content of a dynamic website.
Web servers typically run on a loop, accepting requests from the public as long as it is running. It is also responsible for handling secure transactions and other kinds of requests such as cookies and retransmission of data. It is also responsible for making sure that the content it serves aligns with the permissions of the user who asked for it.
A web server can be deployed in various ways, such as in a cloud, on a physical machine, or on a virtual machine. Web servers can also be managed remotely, allowing system administrators to manually control the servers from a distance.
Today, web servers are an integral part of the World Wide Web, enabling websites and applications to be experienced online. It is responsible for the delivery of content to millions of users around the world.