A general officer is an officer of high rank in the army, and in some nations' air forces or marines.
The term "general" is used in two ways: as the generic title for all grades of general officer and as a specific rank. It originates in the 16th century, as a shortening of captain general, which rank was taken from Middle French capitaine général. The adjective general had been affixed to officer designations since the late medieval period to indicate relative superiority or an extended jurisdiction.
Today, the title of "General" is known in some countries as a four-star rank. However different countries use different systems of stars for senior ranks. It has a NATO code of OF-9 and is the highest rank currently in use in a number of armies.
The various grades of general officer are at the top of the military rank structure. Lower-ranking officers in land-centric military forces are typically known as field officers or field-grade officers, and below them are company-grade officers.
There are two common systems of general ranks used worldwide. In addition there is a third system, the Arab system of ranks, which is used throughout the Middle East and North Africa but is not used elsewhere in the world.
Variations of one form, the old European system, were once used throughout Europe. It is used in the United Kingdom (although it did not originate there), from which it eventually spread to the Commonwealth and the United States of America. The general officer ranks are named by prefixing "general", as an adjective, with field officer ranks, although in some countries the highest general officers are titled field marshal, marshal, or captain general.