Game Help What are Terminus enemies in Space Marine 2?

Just got a bolt rifle that dropped with a perk that lets me deal 10% increased damage to Terminus enemies in the game, uh only problem is this is m first warhammer 30k game so anyone know what the Terminus enemies are here pls?
 
Hey man, hope you're enjoying the 40k world for the first time
Anyway, these Terminus enemies are basically your boss enemies

Anything that gives you a boss health up the top when you're near them or facing them