Okay kiddo, imagine you have a lot of toys and you want to put them all in one big toy box. But if you just throw them in there, it will be hard to find the one you want later. So, you decide to put different toys into different smaller boxes first, and then put those boxes into the big toy box. This way, you can find the toy you want more easily.
In the same way, a Moose File System is like a big toy box for computer files. But instead of small boxes, there are different areas for different types of files, like pictures or documents. This makes the files easier to find and organize.
And just like how you can add more toys to your toy box anytime, you can also add more files to the Moose File System anytime!