Draco is a tool that helps make really big computer files smaller.
Think of it like packing a suitcase for a vacation. If you just throw everything in the suitcase, it will be really heavy and hard to carry. But if you fold your clothes neatly and use a special vacuum bag to remove the air, your suitcase will be much lighter and easier to carry.
Draco does something similar with computer files. It takes all the information in the file and compresses it, so that it takes up less space on your computer. This can be really useful if you need to send the file to someone else, because it will take less time to send and won't take up as much space in their computer either.
But just like packing a suitcase, sometimes you have to sacrifice a little bit of quality to make the file smaller. It's kind of like if you try to pack too many clothes in your suitcase, they might get wrinkled or squished. So, sometimes when you use Draco to compress a file, the quality might not be quite as good as the original. But for many types of files, the difference isn't noticeable at all, just like how you might not notice if your shirt has a few wrinkles when you're on vacation.
Overall, Draco is a really helpful tool if you need to pack a lot of information into a smaller space.