Minecraft wiki entry for Redstone_circuits, associated text: A useful distinction can be made between a circuit performing operations on signals (generating, modifying, combining, etc.), and a mechanism manipulating the environment (moving blocks, opening doors, changing the light level, producing sound, etc.). Making this distinction lets us talk about the various circuits separately, and let players choose whichever circuits are useful for their purposes. The machines controlled by redstone circuits can range from simple devices such as automatic doors and light switches to complex devices such as elevators, automatic farms, or even in-game computers. However, this article provides only an overview of redstone circuits as above. These can be used to control simple mechanisms, or combined as parts of a larger build. Each circuit type on this page has links to its own page, which provides greater detail about them and give schematics for multiple variations of each.