A q document is a special type of paper that people use for writing things down. It's called q document because it has a special coating on it that allows you to erase things you've written with a special eraser.
Imagine you're drawing with a marker on a whiteboard. If you make a mistake, you can't erase it because markers don't erase easily. But with a q document, you can erase things just like you're using a pencil or an erasable pen.
This kind of paper is really useful for people who need to write lots of notes, like students or people in business, because you can revise your notes easily and not waste paper. It's also really cool because you can use it over and over again, so you don't need to buy new paper all the time.
Overall, q document is just special paper that lets you write and erase things easily, which can be really helpful and save money in the long run.