How Pumps and compressors mechanism work?

Answer 1

all you need to learn is available at wikipedia
A pump is a device used to move liquids, or slurries. A pump moves liquids from lower pressure to higher pressure, and overcomes this difference in pressure by adding energy to the system (such as a water system). A gas pump is generally called a compressor, except in very low pressure-rise applications, such as in heating, ventilating, and air-conditioning, the equipment is known as fans or blowers.
source:wikipedia