What is direct burial wire?

Question

What is direct burial wire?

Answer 1

It's wire that can be buried underground without the need of conduit (metal pipe). It will be labeled with a U and has proper sheathing (thicker than the non-burial wire).

Answer 2

Direct burial wire has a thicker and more waterproof insulation. Which allows you to use this underground without running it in conduit.

However if being used above ground it will need to be protected from sunlight.