Major general (abbreviated MG, maj. gen. and similar) is a military rank used in many countries. It is derived from the older rank of sergeant major general. The disappearance of the "sergeant" in the title explains the apparent confusion of a lieutenant general outranking a major general, whereas a major outranks a lieutenant.
In the Commonwealth and in the United States, when appointed to a field command, a major general is typically in command of a division consisting of around 6,000 to 25,000 troops (several regiments or brigades). There, it is a two-star rank that is subordinate to the rank of lieutenant general and senior to the rank of brigadier or brigadier general. In the Commonwealth, major general is equivalent to the navy rank of rear admiral, and in air forces, with a separate rank structure, it is equivalent to air vice-marshal.