Apache Software Foundation developed an open-source web server, name as Apache HTTP Server usually called just apache.

These days around 50% of all websites are hosted and running on Apache web server; Apache is the most popular web server on the internet.

Previously we using NCSA HTTPD web server, Apache web server project is based on NCSA HTTPD and it launched in 1995.

The Apache web server software is free and open-source, licensed under the Apache license that allows users to use this web server software with full freedom for any purpose like to distribute, to modify and to distribute a modified version of the software.

Apache web server software support cross-platform. It is available for several operating systems:

• Windows
• Linux
• OS X
• Unix
• Solaris
• FreeBSD

Apache web server software has many features, and its functionalities can extend using the compiled module. There are multiple modules available which can help you to extend the function and capabilities of the web server for your hosting web sites.

These are some significant features of the Apache web server:

• Capable of handling a large volume of traffic
• Feature of Virtual host enables to host multiple websites in single web server
• Functionality to configure error messages of a web server
• It supports several graphical user interfaces (e.g., ApacheConf)
• It supports digital certificate authentication
• It supports password authentication for private web sites
• It supports load balance across multiple web servers
• It supports proxy server functions also.