Imagine you have a big toy box with a lot of toys inside. When you want to clean up your room, you have to decide which toys you want to put away and which ones you want to keep out to play with.
The staging area is like a small box that you use to sort your toys before putting them away. You take toys from the big toy box and put them in the staging area to decide if you want to keep playing with them or if they should be put away.
Similarly, when you're working on a project on your computer, you have to decide which changes you want to save and which ones you want to discard. The staging area is where you put the changes that you want to save before committing them to the final version of the project.
In simple terms, the staging area is like a temporary storage area that helps you decide what changes you want to keep and which ones you want to discard before making them permanent.