Whats the difference between alt rock and prog rock?

[AvengedVirginity]

BQ1: if you had to would you rather listen to linkin park's or papa roach's entire discography?

 

[Faceplant]

This is alt rock: Radiohead, R.E.M., The Smiths, The Cure, Violent Femmes

This is prog rock: Yes, Pink Floyd, Rush, Emerson Lake & Palmer, Jethro Tull