I am fine with the basics (e.g. classical vs rock/punk vs pop based on instruments) but there’s loads of other terms that aren’t very intuitive.

What is the difference between “alternate” rock and I guess “regular” rock? What is the difference between rock and punk? What is post-(insert subgenre here, like punk)? What is pop rock (the music subgenre, not the fizzy candy rocks), and how is it different from rock pop? What makes music “progressive”? What on earth are the “blues”? What is the difference between rock, metal, hard metal, heavy metal, etc. aside from an increasing level of angriness and decreasing level of clarity? etc etc