Thrusters are a type of rocket engine that can generate thrust in a specific direction. They are commonly used for spacecraft maneuvering, station-keeping and attitude control. Thrusters work by expelling propellant in a direction opposite to the desired movement, creating an equal and opposite force that moves the spacecraft in the desired direction. They are different from main engines, which provide the primary propulsion for a spacecraft, and are typically used for launch and interplanetary travel.