A fireteam is a military unit. It is the second smallest unit in a military force.
A USMC fireteam consists of four men: A Rifleman, the jack-of-all-trades, the Grenadier, the explosives expert, the Automatic Rifleman, the supression expert and the Assistant automatic rifleman, replaced with the Scout in Operation Flashpoint: Red River.
The PLA do not use the fireteam but instead use the three-man cell.
The ETIM have classes but it is unknown whether they use the fireteam structure.