The Libraries section under file explorer in Windows is your go-to place for many of the important files on your PC. It is divided into Documents, Music, Pictures, and Videos.
This is the default save location on your PC when you add those types of files. So, if you’ve written a document and can’t find it — look in that documents folder first. Same goes for music, pictures, and video.
You might be tempted to make your own folders somewhere else, but I would suggest making any folders you need for organizing files within the library. This is where backup software will look for your files. That way when you need to back up the files or move them to a new PC, copying the library files will take care of the vast majority of your personal files.