An administrative share is like a secret room that only special people, called administrators, can access. Just like how your mom and dad have a special key to the garage or attic in your house, administrators have a special password to access the administrative share on a computer.
This administrative share lets them see all the important files and folders on the computer that regular users can't see. For example, they can see things like passwords, user accounts, and settings for the whole computer. It's important to keep this share secret so that bad people can't access it and do bad things like steal information or mess up important settings.
So essentially, the administrative share is a special place on a computer that only certain people have access to, and it contains really important information that needs to be protected.