Python is an open source interpreted programming language used in many GIS programs.
Python is a dynamic and strongly typed general purpose programming language. It has an extensive standard library and a community-run index of third-party packages: PyPI. The language is free and open source, even for commercial use; its license is managed by the Python Software Foundation.
There are additional questions and answers on StackOverlow python's tag for Q&A about python outside of GIS. There could be some related to GIS but they should most likely be moved over to GIS.