As mentioned above, Positivism and Post-positivism are not methodologies, but paradigms. This video seems to explain them in a rather simple way: https://www.youtube.com/watch?v=f0oQ3a9ATbM
Yes, I agree with Kelvyn Jones and Nicolò Zarotti, these are paradigms. Please find a good website which explains the difference: https://conjointly.com/kb/positivism-and-post-positivism/#:~:text=Positivists%20believed%20that%20objectivity%20was,perfectly%20as%20it%20really%20is.
To me they are philosophies of knowledge- ontology (what exists in the world) and epistemology (how can we know it) and there may be links to methodology. For me there is not a one to one connection between the philosophy and method - in particular quantitative method does not mean a positivist approach to knowing despite what the literature often assumes. I find the term paradigm a bit slippery - it has been claimed that Kuhn used it in 21 different ways in the structure of scientific revolutions!
This chapter discusses positivism, social constructionism and critical realism