Urban dictionary:
Brostep is a newer sub-genre of dubstep. It is usually more aggresive and louder than traditional dubstep. Most Americanized dubstep is considered brostep. For example Skrillex is considered brostep. Most dubstep fans hate brostep.
The goal appears to be to produce music as fast as you possibly can, without placing any emphasis on quality.
Unlike Dubstep where sub bass is key, Brostep places more emphasis on ratty high frequency samples and oscillators that arent even low frequency. Toss in a few hip hop vocal samples and you are well on your way to being the worlds next big Brostep producer.
Pretty much dubstep.
