I always thought of Rap being the more aggressive of the two, with aggressive lyrics and the worse music out of the two. It's hard to explain, I don't know. (Some Rap music has really smurfing crap music.) I'd class a lot of mainstream stuff under rap. Hip Hop I always thought had more upbeat music and messages, and generally old school stuff and pretty cool, a lot better. Stuff like De La Soul, that's what I think of as Hip Hop.