There is a difference.

Hip Hop is tha culture. It's tha basic category of this type of music. Another form of hip hop is now called backpack rap. I hate that it's called that but thats how tha industry has evolved.

Rap is a subcategory. Rap is str8 gangsta, streetz, club type shit. I'ts what you hear on tha radio day in and day out. Rap is tha money maker.