Okay, so think of your computer like a big, organized toy box. Just like how your toys have their own spots in the toy box, files and data on your computer are also organized into different areas.
One of the tools that helps "box" up your computer's data is called gpart. It's like a special helper that gets your computer's "toy box" in order, so that you can find and access the files you need more easily.
Gpart helps you create and manage these different "boxes" that hold your data. So if you need a special box just for pictures, gpart can create one for you! And if you decide later that you need a bigger toy box just for videos, gpart can also help you resize and make changes to your data boxes.
Overall, gpart is like the toy chest organizer that helps you keep all of your computer's files and data tidy and easy to find.