A groupset is a collection of components that make up the drivetrain of a bicycle. It typically includes the crankset, chain, cassette, derailleurs, and shifters. These parts work together to enable smooth gear shifting and efficient power transfer from the rider to the wheels. Groupsets are categorized by their level of performance and intended use, such as road, mountain, or hybrid biking. Popular brands like Shimano, SRAM, and Campagnolo offer various groupsets tailored to different cycling styles and budgets, allowing cyclists to choose the best fit for their needs.