Bucket

A bucket is a utility item used to carry water, lava, milk, powder snow, and the sulfur cube.

Empty buckets can be used to "pick up" a water or lava source block by pressing use item on a block of the relevant type. If the empty bucket is part of a stack and the player's inventory is full, the filled bucket drops in front of the player as an item.

A bucket filled with a source block can then be used to place its source block contents in the empty block next to the side of the block the player is currently looking at, or replacing the block looked at for some replaceable blocks.