What is the difference of Rap Metal and Nu-Metal?

Answer 1

Rap Metal is more heavy with Rap vocals, some Hip-Hop rhythm sections, and sometimes with Turntables.

Example: Rage Against the Machine, Public Enemy & Anthrax, Street Sweeper Social Club, P.O.D., and and some songs from Cypress Hill.

Nu-Metal does have the same as Rap Rock but not heavy enough, and it's more Rock, Alternative, and Post-Grunge than Metal music. Sometimes Nu-Metal doesn't need Rap vocals or Hip-Hop rhythm sections, it can use electronic beats, screaming, or just singing.

Example: KoRn, Limp Bizkit, Slipknot, Linkin Park, and Disturbed.