Python is a general-purpose programming language. It can be used for creating almost any application (the only condition is that the guest system should support running the language).
It is a easy-to-learn and a very powerful language at the same time.
There are two main versions: python2 and python3, the 3rd version being the newer. The two versions are not fully-compatible, so there might be issues in using one to run code for the other. The most code from this tutorial will use python3.