Both compress air entering an internal-combustion engine, with the goal of increasing the amount of oxygen available in the fuel-air mixture that enters the cylinders, and thus increasing the amount of energy available to each power-stroke of each piston. A supercharger is direct-driven from the engine itself, typically by a toothed belt from the driveshaft, but occasionally directly from the driveshaft itself. The most common form is an external-compression, or Roots supercharger , which uses counterrotating lobed “rotors” or gears to trap air (or fluid, in other uses) against the inside of an enclosure, and move it from one side to the other. Explaining this is the exact reason animated gifs were invented: Those gifs are two-dimensional (well, three, with the third being time rather than Z, but..) the most common implementation uses three-lobe rotors which have a helical twist, in order to minimize pulsation or “hammering” of the output. It’s wort...