The good guys of the Transformers universe. There were quite an abundant amount of them, the most notable being
Bumblebee,
Jazz,
Ratchet, Ironhide, and Hot Rod/Rodimus Prime. They were all led by the noble leader Optimus Prime. They fought to destroy the evil forces of the Decepticons, the bad guys of the Transformers universe, led by Megatron. That simple.