Major

Major was a military rank that represents an officer that is mid-to-upper level of commission, and often acts alongside or just under a Colonel. It is often a parallel to the Naval rank of Commander or Lieutenant Commander.

Galactic Empire
In the Imperial Army, a Major commanded a battalion.

New Republic
Majors in the New Republic Army were the bridge between book-smarts, and battle-smarts. Typically they acted as either an Executive Officer at the Battalion level or were assigned to a support unit at the Brigade or higher level to gain non-combat command and operational readiness experience. In rare occasions, they were put in charge of a Battalion when there are no other fitting officers. In the case of support personnel, a Major may be in charge of an entire Battalion.

In the New Republic Starfighter Corps, Majors were typically newly-christened aces, with plenty of combat experience. Still the bridge between book-smarts and battle-smarts, they were most often put in charge of their own squadron. In rare occasions, they were put in charge of a Strike Group when there are no other fitting officers. In the case of support personnel, a Major may be in charge of an entire Strike Group's detachment of enlisted personnel and officers.