Maneuvering and attitude-control thrusters.
Maneuvering thrusters can also serve as attitude-control thrusters, but the reverse isn't true.
This is primarily due to their number and placement and, in the case of reaction wheels, their inability to provide translational motion because of how they work.
Attitude control. First, consider the reaction wheel. The system consists of discs spinning at high speed in three different planes. By slowing or accelerating these discs, a craft can change its orientation in space without consuming reaction mass, or fuel. A system like this is used on the ISS. Disadvantages: relatively high mass, periodic calibration, and complex manufacturing. Advantages: no fuel requirement, high precision, and smooth operation. We won't consider solar sails because their force is extremely small.
Next are engines that can be used both for attitude control and maneuvering. The only difference between the systems is the number and placement of their working elements.
Compressed-gas thrusters. These are as simple as possible and equally inefficient. Compressed gas is released through nozzles, where it expands, gains velocity, and produces thrust. Exhaust velocity is hundreds of meters per second. They produce no infrared or visible signature.
Externally heated reaction-mass thrusters. Something between gas and rocket propulsion. An external source, such as a nuclear reactor, heats the reaction mass. It is released as gas through nozzles, where it expands, gains velocity, and produces thrust. It creates no visible signature. Exhaust velocity is hundreds of meters per second.
Chemical-fuel rockets. They use various propellant pairs that provide different thrust, efficiency, and design complexity, but belong to the same class. The propellant burns in the engine's combustion chamber, heats up, expands, and exits through the nozzle to create thrust. Exhaust velocity is 2 to 3.5 km/s.
Electric propulsion: Hall-effect, ion, VASIMR, and similar engines. The reaction mass, usually a gas, is heated to an ionized state, accelerated by an electromagnetic field, and expelled to produce thrust. There are many different designs and operating principles. Their defining feature is extremely high efficiency. Their disadvantages are power consumption and, above all, low thrust. Producing one kilogram-force of thrust requires more than 500 kilowatts of power. Exhaust velocity of the gas or plasma is 8 to 50 km/s.
Solid-propellant units. They can be started once or several times. Their thrust can't be regulated, and they require replacement. They aren't suitable for attitude control.
Hybrid units are similar to solid-propellant ones but allow thrust regulation.
