Python is an interpreted programming language that is often, but not solely, used as a scripting language. A version of Python is included by default on all Ubuntu distributions.
Python is a general purpose language which can be used for anything from quick scripting jobs to fully object-oriented GUI programs.
Python is designed to have readable source code. As such, code blocks are delimited by indentation instead of the braces used in many other languages. Python is one of few programming languages to have significant white space.
Unlike C-like languages, Python is generally not compiled and is instead an interpreted language. The most common interpreter is CPython, which is written in C. Other interpreters are PyPy, which is written in Python and Jython, which is written in Java.
From http://hg.python.org/peps/rev/76d43e52d978 (PEP 373, Python 2.7 Release Schedule):
The End Of Life date (EOL, sunset date) for Python 2.7 has been moved five years into the future, to 2020. This decision was made to clarify the status of Python 2.7 and relieve worries for those users who cannot yet migrate to Python 3.