It’s an HTTP Server built by Apache Foundation. HTTP Stands for Hypertext Transfer Protocol, which decodes Hypertext and Multimedia documents through a server-side program. An HTTP daemon (background process) program runs and serves the requests from any HTTP client like a Web Browser. It is important to note that Apache HTTP Server can only serve static content like text or media that doesn’t change during the web page loading. To serve the dynamic content via scripts technologies/protocols like Common Gateway Interface (CGI), Java Server Pages (JSP), etc. are being used.
What Are Apache Modules?
As stated above, Apache HTTP Server is a basic web server that can be used to serve non-dynamic content. Still, it also doesn’t provide any functionalities like Authentication, Encryption of requests, Logging, Support, SSL, Heartbeat, LDAP, Caching, etc. So, it provides special program modules to extend the core Apache HTTP Server's functionality.