Okay kiddo, imagine you are playing a game of hide and seek, but instead of just using your eyes to look for your friends hiding in the room, you use a really long straw with a mirror inside that you can peek through. That's kinda what a periscope is!
Now, imagine a special kind of straw that's attached to a big gun. This straw is called a periscope rifle. This rifle is used by soldiers in the army to help them see and aim at faraway targets without getting too close and risking their safety.
The periscope part of the rifle is like a long tube that sticks up from the top of the gun, with mirrors inside that help the soldier look around corners or over walls without exposing themselves. The rifle part of the gun is used to actually shoot bullets.
So, when a soldier is using a periscope rifle, they can stay hidden behind cover while looking and aiming at their target. This makes it much safer for them to shoot at their enemies from far away.
It's important to remember that guns and weapons are very serious things, and should only be used by trained professionals like soldiers who follow strict rules and protocols to make sure they are using them safely and responsibly.