>>7534235Emperor of Mankind is a living god who's currently on life support; he led humanity to a golden age before he got ganked and everything became a horrible dystopia.
Primarchs are 20 demigods created from his genes who served as his generals before all dying/disappearing. Also half turned evil.
Custodes are elite super warriors that guard the Emperor.
Astartes are the Space Marines, elite supersoldiers that are bullshit OP, but somehow not as much as the aforementioned things. Humans can become Astartes through a certain process, but the augments and training are so harsh that their numbers are incredibly limited.
Primaris marines are new; think of them as Space Marines 2.0.
