A battle axe is a tool that was used a very long time ago to chop and cut things, like trees or animals for food. It is made of metal and has a long handle that you hold onto with your hands.
The top of the axe, which is called the head, is the part that does the chopping. It is shaped like a wedge or a triangle, with a sharp edge at the bottom that is used to cut through things.
People used to use battle axes for fighting in battles a really long time ago, like in medieval times. Soldiers would swing them at their enemies to try to hurt them in battle.
Nowadays, people don't really use battle axes anymore for chopping things or fighting. They are just seen as cool or interesting historical artifacts.