Okay kiddo, so imagine a big, strong animal that is as tall as a tree, weighs as much as a house, and has really powerful legs to stomp on things. That's what a war elephant is!
Now, during the Persian Wars, a long time ago in ancient history, some armies in Persia used these war elephants for battles. They were very powerful and could knock down any soldiers or obstacles in their way.
These elephants could also carry soldiers on their backs and they would charge into battle together. It was a scary sight to see for the opposing armies because they knew they were up against something very strong and hard to beat.
What's interesting is that some of these war elephants were trained to wear armor, just like knights in shining armor! This made them even harder to beat because they were extra protected.
However, war elephants were not invincible. They could be taken down by certain weapons, like arrows or spears, if an enemy was quick and clever enough.
So that's it, kid. In summary, war elephants were big, strong animals used in ancient battles for an advantage on the battlefield. Hope that helps!