here are two different pump types – reciprocating and rotary. Reciprocating are suitable for portable and smaller applications. Rotary pumps are suitable for large applications. Reciprocating Pumps – They compress air using pistons which move up and down within the cylinders. They are usually seen in manual bicycle pumps. Rotary pumps – air compressors with this type of pumps have two rotors which turn in opposite directions. Air trapped between will cause compression. As they operate in rotary motion, the compressed air will be transferred from one to another. In general terms, they are referred as centrifugal pumps. They are usually used in clothes dryer.