So I see questions around these terms very often in our growing Python Bangladesh community. Most of the times beginners are confused about what is what. I hope I can refer to this blog post to explain the similarities and differences. pyenv Have you ever wanted to test your code against multiple versions of Python? Or just wanted to install a newer version of Python without affecting your existing version? May be you heard about PyPy a lot and want to install it on your machine? If you did, then pyenv is the perfect tool for you. It allows you to easily install multiple copies and multiple flavors of the Python interpreter. So you can not only install different versions of CPython, you can also install PyPy, Jython, Stackless Python and their different versions. The tool provides a nice command line tool to easily swap out the global python interpreter. It also allows to define per application python version. You can use it’s local command or directly mention a p