The Terrans are split into 3 groups.  The lowest is the Omega Squadron, the middle is the Alpha Squadron, and the finest of them all are the few that call themselves the Elite Guard.  Each group has a general, and he may appoint as many as 5 to the other ranks.

General:  This is the head of a group, he also is that groups trainer, and he is the representative to the Congress. He also assigns special assignments, ex. The captain may have a special assignment as map maker.

Colonel:  This is the person who is in charge of a small detachment of marines and can be the personal adviser of the general.

Major:  This is a person who is supposed to take orders.  However, it is a good position as he is one step away from a major position.

Captain:  He is the highest ranking soldier and it is a good position to be in because you do not have to deal with all the negotiations and meetings that the officers do but you get to battle a lot.

Lieutenant:  This is a step up from the marine and should be easy to get to quickly.

Marine:  This is the lowest position in the terran ranking system, but it is one of the best!  You are the army that will take its orders and destroy anything in its path.