Types of compressor & categorisation:
- The two main air compressor categories are split into two: positive displacement and dynamic. Under these umbrella categories fall many other categorised forms of air compressor, which have been characterised based on these aspects:

Whether the air compressor is single-stage, 2-stage, or multi-stage.
The cooling method is taken into consideration and if it is cooled, water-cooled, or oil-cooled.
Next is the drive types, or how the air compressor is driven, which can be either engine-driven, motor-driven, turbine-driven as well as many other components.
The air compressors method of lubrication, further categorised into splash lubrication, forced lubrication or oil-free compressors.
Finally, the service pressure and whether it is low, medium, or high, can also determine the air compressors category.
Reciprocating compressors, that fall under the positive displacement umbrella term, are the most commonly used compressors. These are either diesel engine driven air compressors, or directly driven by electric motors.