Its an alternative to Python. Its essentially Python + a bundle of different packages & libraries listed on the previous page such as: NumPy, Pandas, SciPy... which come right out of the box without you having to install them separately.

Video Tutorial Explanation:

https://www.youtube.com/watch?v=YJC6ldI3hWk

I also suggest using Anaconda First, which is a bundle of all the necessary libraries/packages using in the scientific community with Python although it is not necessary or a big deal.