Lava

Lava is a light-emitting fluid that causes fire damage, mostly found in the lower reaches of the Overworld and the Nether.

Lava can be collected by using a bucket on a lava source block or a full lava cauldron, converting the bucket to a lava bucket. Lava may be obtained renewably from cauldrons, as pointed dripstone with a lava source above it can slowly fill a cauldron with lava (if in the Nether, the source of lava isn't necessary).

In Java Edition, lava does not have a direct item form, but in Bedrock Edition it may be obtained as an item via inventory editing or add-ons.