The term 'Fast Flyer' refers to two different types of aircraft: a JET and a supersonic transport (SST). A JET is an aircraft powered by JET engines, which use air intake to create thrust. An SST is an aircraft that can travel at speeds greater than the speed of sound. Both jets and SSTs are capable of reaching high speeds, making them ideal for long-distance travel. The combination of these two aircraft makes the term 'Fast Flyer' an apt description.