OK, understood. This shit's complicated, so please pay attention.
There is rock. There is pop. And there is pop rock.
Rock is heaviness and grit and also power of weightier instruments like guitars and drums to add catchy melodies to.
Pop is softer, and uses catchy melodies in a soft background, with a chirpy and often upbeat sound, with little grit but bassy. Pop refers to all sorts of popular music like hip-hop, country, R&B, bubblegum pop, jangle pop, folk, singer-songwriter, K-Pop, and kids music.
Pop rock is the intersection of pop with rock.
Fleetwood Mac was British Blues originally but eventually turned to pop rock.
Steve Miller is rock blues, psych rock, Southern rock.
Joe Walsh is hard/blues/pop/progressive/country rock.
