Dubstep (also known as dubstep remix or remix dubstep) is a genre of music that started in South London, it drew influence from 2-step garage, dub, drum and bass, grime and reggae. A popular dubstep producer Skrillex changed the genre into something much heavier with more growls, gritty basslines and fat sub-basses.
Since then, the dubstep scene has changed a lot with dubstep going from the underground genre that it was to a mainstream one. It has been played on big festivals, like Ultra Music Festival and Lost Lands.