If you don't know yet, we tell you a bit about these valuable things in our fanart Minecraft Iron Ingot and Pistons cursor pack. A piston is a block capable of pushing blocks, players, and mobs when given a redstone pulse. A sticky one has the same function as a standard piston but can also pull the block on its face back when it retracts, unlike the regular piston, which leaves the pushed block in place. This gray thing is an iron ingot - a versatile metal ingot used extensively in crafting.
