The Diesel Cycle is a thermodynamic cycle that describes the functioning of a diesel engine. It consists of four main processes: isentropic compression, constant pressure heat addition, isentropic expansion, and constant volume heat rejection. This cycle is characterized by the use of compression ignition, where air is compressed to a high pressure and temperature, allowing fuel to ignite spontaneously. In the Diesel Cycle, the efficiency is generally higher than that of the Otto Cycle, which is used in gasoline engines. This is due to the higher compression ratios and the nature of the fuel used. The cycle is essential for understanding how diesel engines operate and their applications in various vehicles and machinery.