A troop carrier is a means of transporting soldiers. A troop carrier vehicle may be configured for troop transport while used for other purposes at other times.
The Douglas C-47 Skytrain is an aircraft used as a troop carrier; the Boeing CH-47 Chinook is a helicopter designed for it, though often used for other purposes. Military transport aircraft evolved from bombers.
The Nissan Patrol is a four-wheel drive vehicle with a model suited for use as a troop carrier.
A troopship is a ship that serves the purpose.
Armoured personnel carriers also are troop carriers.
The Leamington Transit was an electric railway in Canada that carried troops during World War I.