Managing Multiple Python Versions with pyenv

In my Python journey, I've always stuck to just one version of Python at a time. I happily used Python 3.9 for quite a while, then switched to Python 3.10 without any issues. Everything was perfect until recently when I tried installing a Python application using pip, but no matter what I did, the installation kept failing. I couldn't fix the issue even after hours of Googling.
That's when I finally decided to check the documentation (which I should have done from the start), and there it was, this application requires a minimum Python version of 3.8 and was only tested on versions 3.8 and 3.9. That made me think, maybe I should have installed it using Python 3.9, but how? I'm no expert in Linux or Unix systems, and I worried that reinstalling Python 3.9 could mess up other projects I'd built on 3.10.
So, I started exploring how to manage multiple Python versions on the same machine, and that's when I stumbled upon a tool called 'pyenv'. This seemed like the perfect solution to my problem, so I decided to learn more about it.