This document provides an overview of compressors, including: - Positive displacement compressors that mechanically reduce the volume occupied by air/gas to increase pressure, including reciprocating and rotary screw compressors. - Dynamic compressors that impart velocity energy to continuously flowing air/gas through impellers to increase pressure, including centrifugal and axial compressors. - Advantages like increased pressure capabilities and versatility across industries, and disadvantages like noise, energy use, and maintenance needs. - Applications in industries like manufacturing, construction, HVAC, oil/gas, aerospace, medical, food/beverage, and automotive.