photography beginners

When I upload my RAW photos to my computer, why does it lose its picture quality? I would like to know how to edit my RAW photos without losing the picture quality. I’ve tried editing on GIMP but it will lose picture quality.

Hey when i started learning photography i remember that i had a really hard time finding good quality formations online and I finally paid for expensive formations and classes. And recently i had a think, wouldn't be great if you could nowadays simply go on youtube and find all you need to learn...