Okay kiddo, have you ever played a game with your friends where you have a secret code language and only you and your friends can understand it? Well, the military has something like that too called NIPRNet!
NIPRNet is a special computer network that the military uses to share important information between different branches of the military, like the Army, Navy, Air Force, and Marines. Just like how you can only share secret messages with your friends who know your code language, the military can only share information on NIPRNet with people who have security clearance to access it.
But why do they need a special computer network for sharing information? Well, imagine if you had to send a really important message to your friend, but you had to use your regular phone that anyone can listen in on. You wouldn't want anyone else to hear your secret message, right? That's why the military has NIPRNet, so they can send important messages and share information without others outside of the military listening in.
So, NIPRNet is like a secret code language but, for the military to share important information. Does that make sense, kiddo?