Okay kiddo, so you know what a gun is, right? Well, the M231 firing port weapon is a special kind of gun that is used in military vehicles like tanks and armored personnel carriers.
Now, you know how sometimes soldiers need to shoot at bad guys while they are inside the vehicle? But it's really hard to turn around and aim a regular gun in such a cramped space. That's where the M231 comes in!
The M231 is a tiny gun that is mounted on the side of the vehicle, right next to a small window called a firing port. The soldier inside the vehicle can then stick their arm out of the firing port, holding onto a special handle that is connected to the gun.
The gun shoots very quickly and loudly, making lots of noise and smoke. But it is also very powerful and accurate, which is why soldiers use it to protect themselves when they are inside a vehicle.
So basically, the M231 firing port weapon is like a tiny gun that you can stick out of a small window in a military vehicle, and it helps soldiers defend themselves when they can't turn around and shoot a regular gun.