What is CPython?

CPython is the reference and most common implementation of the Python language, written in C. When people talk about 'Python' they usually mean CPython. It includes both the interpreter and the execution environment. Other implementations include PyPy (faster for certain cases), Jython (in Java), IronPython (in .NET), and MicroPython (for microcontrollers). CPython compiles Python code to bytecode before interpreting it.