This document provides an overview of Apache Tomcat, a free and open-source web server and servlet container developed by the Apache Software Foundation (ASF) that implements the Java Servlet and JavaServer Pages (JSP) technologies. It discusses what Tomcat is, its role as a web application container, how to install and configure it, enable features like CGI and SSI, and addresses some common issues. The advantages of using Tomcat include that it is open source, lightweight, easily configured, stable, well documented, and free.