HTTP serving is one of the most visible and “glamorous” function of a server. This is because most people use web resources via a web browser, and therefore know something about HTTP serving. The technical backend of HTTP serving is also quite interesting because of scripting possibilities.
Apache is one of the most commonly used open source web (HTTP) server. While it is not the most compact or efficient, it has many available “modules” to extend the functionality. Apache is a flexible HTTP server that allows a high degree of customization.