Barrel

Barrels are tile entity storage blocks generating in villages.

Natural generation
Barrels can generate naturally in fisher cottages in villages.

Container
Barrels have a container inventory similar to a single chest. They can be filled by droppers and both filled and emptied by hoppers. When broken, barrels drop the contents of the container and the barrel item itself. Unlike chests, a barrel can be placed below a block and still be able to be opened. Plus, they can be placed together more easily (without shifting), which also makes for more efficient storage.

Fuel
Barrel can be used as fuel in Furnace for smelting 1.5 items.

Block entity
A barrel has a block entity associated with it that holds additional data about the block.