From Teletraan I: The Transformers Wiki

In the Generation 1 continuity family, the Predacons are a sub-faction of the Decepticons that eventually evolved into its own major faction after the Pax Cybertronia. They usually take beastly alt modes, but not always.

In the Robots in Disguise continuity the Predacons are an apparently small faction of world-conquering robots with beast alt modes, who are later supplemented by a sub-faction of vehicle-based Transformers called Decepticons.