Creating Tests in UiPath


I would like to understand how I can create something similar to unit-tests. I heard of the REFramework, but it remains completely unclear to me how to create tests and how to use them. I would be very grateful if someone could explain how I should use it with the REFramework or, which would be much better, how I can create tests myself without using the REFramework.

A minimal working example would be a massive addition to it!

Thank you in advance!