A Redstone Repeater is a component in the game Minecraft that is used to extend the range of Redstone signals. It can receive a signal from a Redstone source and transmit it further, allowing players to create more complex circuits and mechanisms. The repeater can also introduce a delay in the signal, which is useful for timing various actions in the game. To craft a Redstone Repeater, players need three Stone blocks, one Redstone Torch, and two pieces of Redstone Dust. Once placed, the repeater can be adjusted to change the delay time, making it a versatile tool for building intricate contraptions and automated systems in Minecraft.