Redstone is a valuable resource in Minecraft, used to create a variety of contraptions and devices. It can be found underground in the form of redstone ore, which can be mined with an iron pickaxe or higher. Redstone ore is most commonly found between layers 16 and 32, but it can also be found in smaller veins at other depths.
Once you have mined redstone ore, you can smelt it in a furnace to obtain redstone dust. Redstone dust can then be used to craft a variety of items, including redstone lamps, redstone repeaters, and redstone comparators. These items can be used to create a variety of useful contraptions, such as automatic farms, item sorters, and even computers.