Okay kiddo, so imagine you are playing with your toys in your room. Now imagine that you have a special toy that you only play with when your friends come over. That special toy is like a private IP address.
An IP address is like a phone number that helps computers talk to each other over the internet. Private IP addresses are like special phone numbers that you use only in your own home, instead of sharing with others on the internet.
They usually start with numbers like 192.168 or 10.0, and are used by devices on your own network (like your phone, computer, or tablet) to talk to each other. They are called private because they are not meant to be used on the wider internet where lots of people can see them.
So, just like your special toy, private IP addresses are meant to be used only in your own home network to make it easier for your devices to talk to each other.