A compressor is one of the lifelines of any industry. Many industrial systems depend on compressed air to perform their basic function. The basic objective of this e-learning module on ’compressor’ is to enhance knowledge of the working principles of various types of air compressors like screw compressors, centrifugal compressors, etc., function and application as well as their classification. In this e-learning module, participants will also learn how to shoot the trouble in a compressor.