Minecraft wiki entry for Furnace, associated text: Furnaces function as multiple real-world devices combined into one block: bloomeries and blast furnaces (for smelting ores), ovens (for baking and cooking), charcoal pits (for the charring of wood) and kilns (for baking of clay).
In Bedrock Edition, the lit furnace block was legitimately obtainable by mining a furnace that is smelting an item while the pickaxe has Silk Touch. When highlighted in the inventory its name was 'lit_furnace'.