A hip hop instrumental is colloquially referred to as a beat, and its composer is referred to as a programmer or beatmaker. In the studio, however, a hip hop producer also functions as a traditional record producer, being the person who is ultimately responsible for the final sound of a recording, for guiding the artists and performers and giving advice to the audio engineer on the selection of microphones and effects processors and on how to mix the levels of the rapping and beats. Most Hip Hop Producer's started out as beatmakers before taking over the acting role as a record producer. Those that do both roles wearing two hats are referred to as Songwriter/Producer's. They are generally credited twice for both acting roles in production credits.
https://en.wikipedia.org/wiki/Hip_hop_production