I am not a big rock fan at all but I sometimes have trouble telling the differences between each bands, etc. Like the genre. I know there are many genres in rock music like metal, trash metal, death metal, emo, punk, power-punk, goth, soft rock etc ...

But how are these bands I listed differ from each other? Are they all different rock genres? Someone break down each one:

Nickelback, All-American Rejects, Avenged Sevenfold, Korn, Yellowcard, Metallica ....

and what is power-pop rock?

An entire list of rock genres:
http://en.wikipedia.org/wiki/List_of_rock_genres

It'd be a hassle to explain everything, so you can look up the ones you're inquiring about.

Powerpop is more a mix between pop and rock, nothing too hard/edgy or too soft.
http://en.wikipedia.org/wiki/Power_pop

So like Wiki says, All American Rejects would be powerpop along with Green Day or Blink 182. If you take the time and listen to them, you'll probably see they have something in common. Obviously being more different than say, screamo or metal.

By the way... Metal is it's own genre. Deffinately not a sub-genre of rock music.

Technically it is... metal evolved from hardcore punk, punk being a sub-genre of rock.

Some bands from each genre you listed:
Thrash metal - Megadeth, Testament, Kreator
Death metal - Death, Morbid Angel, Possessed
Emo - Rites Of Spring, Moss Icon
Punk - The Ramones, The Sex Pistols
Power-punk - ?!
Gothic ROCK - Bauhaus, Siouxsie & the Banshees
Gothic METAL - Macbeth, Beseech, Silentium
Soft rock - ABBA


Look these bands up, and you should be able to hear the differences in styles if you have an ear for music.

power-pop is like cute is what we aim for, hellogoodbye, cartel, etc.