Power pop and Pop rock

I've been thinking and researching lately (which is why i chose the book template) and Power pop and Pop rock both emerged around the same time. And coincidently their names have the same meaning. the "rock" in the word pop rock obviously means rock, and the pop in pop rock obviously means pop, but the power pop genre? The "power" implied in power pop means rock, because it's powerful, guitar powerful, but then next to it it say pop? So obviously the pop in power pop means pop, but i would think the "power" refers to rock music. So that would mean pop rock and power pop are the same. And they just happen to emerge in the same time? Plus, if you look up reviewers definitions for the genres, one says "power pop, it implies crisp vocals, promiment guitar riffs, and minimalistic guitar solos." And describing Pop rock, some reviewers say something like "Pop rock, has rock based guitar playing, but pop style vocals." So im starting to think power pop might be more pop-oriented then pop rock? I've herd my favorite rock band The Cars called a power pop band and Pop rock band an equal amount. But i know The Cars werent peer pop rock, and definetly not power pop, maybe Just What I Needed and You Might Think were a little power pop, but definetly not songs like Youre All Ive Got Tonight and Bye Bye Love. So i just dont know, does anyone have a different opinion??