Bucket carries water, lava, milk, powdered snow, and aquatic mobs for survival control.
Java Edition Guide
Place three iron ingots in a V-shape on the crafting grid.
Right-click water, lava, milkable mobs, powdered snow, or compatible aquatic mobs.
Use water for safe drops and farms, lava for fuel or obsidian, and milk to clear effects.
Check the target dimension before using this item; behavior can change outside the Overworld.
Yes. An empty bucket can collect lava source blocks, and a lava bucket smelts 100 items as furnace fuel.
Placed water can prevent fall damage if the player lands in it, which is why water buckets are common exploration gear.
Buckets can carry fish, axolotls, and tadpoles, but not most land mobs.