The term "50 cc" refers to the engine displacement or capacity of a motorcycle or other small engine. The "cc" stands for cubic centimeters, which is a unit of volume used to measure the capacity of an engine. In this case, 50 cc means that the engine can displace 50 cubic centimeters of air and fuel mixture during each complete engine cycle.
Engine displacement is often used as an indicator of the power and performance of a vehicle. In the case of motorcycles, a 50 cc engine typically represents a small and relatively low-powered engine. These types of engines are commonly found in small scooters or entry-level motorcycles designed for urban commuting or beginners.