The generic actor entity is like an AI with no purpose, not until you give it one. They are commonly used for NPCs that you don't fully interact with, they can be considered "cheap" AI for cinematic purposes.
They are neutral to everyone, which saves creating AI_Relationships.
They are killed in a single hit.
They are not armed by default, further editing may be required to equip them or add attachments.
They can be any character.
They can be made to talk using the logic_choreographed_scene entity.
They can be made to move using the scripted_sequence entity.
Requirements for Usage
A good bit of scripting is necessary to use Generic Actors to their full extent, using a Scripted Sequence you may manipulate a number of settings, including: movement animations, action animations, how to move to it, whether to loop the set action or post idle animation and what should happen upon their deaths.