From Minecraft Wiki
Iron may refer to:
Blocks and items
Iron Ingot − an item created by smelting Iron ore, used for crafting.
Iron Ore − an ore found underground, and the item obtained by mining it.
Iron Nugget − an item obtained by smelting Iron tools, weapons, or armor in a furnace.
Block of Iron − a block used for compact Iron storage, to create Iron Golems and to create the base/pyramid for a Beacon.
Iron Bars − a block that functions exactly like glass panes.
Iron - an element included in the Education Edition Chemistry Update.
Mobs and entities
Iron Golem − a neutral mob which targets neutral or hostile mobs to protect villagers.
Tools, weapons, and armor
Iron Horse Armor