Abstract The main equipment and their subsystems are described in this chapter. Different types of steam generators/boilers such as corner fired, front fired, opposed fired, down shot fired are depicted. The flue gas path with regenerative air heaters of each type of boilers are also described. Type of mills/pulverizers, turbines with all basic types such as impulse, reaction, etc. are included with schematic diagram. Turbine start up system and thermal stress management system are included with figures. All sorts of fans (centrifugal and axial), pumps(BFP and CEP), and heaters/heat exchangers are depicted elaborately. Gas turbines are included separately with all types of cold start ups. Major subsystems namely FO system, AHP, CHP, CTs, DM plants, CW system, ESP, etc. are also taken care of suitably. Reasons of boiler tube failures are described in details. The generators/alternators are depicted to give preliminary knowledge on the same.