A galaflop is a unit of measurement used to quantify the performance of computer systems, specifically in terms of their ability to perform floating-point operations per second (FLOPS). One galaflop is equal to one billion (10^9) FLOPS. The term is often used in the context of high-performance computing and is part of a hierarchy that includes teraflops (trillions) and petaflops (quadrillions). It helps in comparing the computational power of different systems.