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What is a Web Server?

A Web Server is a software application which handles HTTP requests sent by the HTTP client, like web browsers, and returns web pages in response to the clients. Web servers usually deliver html documents along with images, style sheets, and scripts.

Most of the web servers support server-side scripts, using scripting languages or redirecting the task to an application server which retrieves data from a database and performs complex logic and then sends a result to the HTTP client through the Web server.

Apache web server is one of the most commonly used web servers. It is an open source project.

Web Application Architecture

A Web application is usually divided into four layers −

• Client − This layer consists of web browsers, mobile browsers or applications which can make HTTP requests to the web server.
• Server − This layer has the Web server which can intercept the requests made by the clients and pass them the response.
• Business − This layer contains the application server which is utilized by the web server to do the required processing. This layer interacts with the data layer via the database or some external programs.
• Data − This layer contains the databases or any other source of data.