Apache ANT is a java build tool. ANT is released by Apache to build JAVA applications easily.
When working on large scale projects, there will be a number of tasks to be deployed and published every-time, which wastes a lot of time. Here, ANT makes use of commands (consisting of XML files) to control these several tasks.
It is possible to extend with other languages as long as they have JAVA bindings, but in reality, most people use JAVA to extend ANT.
But before learning, it is better to have an idea about: