Perhaps you wanted to tweak something using a tip from Macworld, Mac OS X Hints, or elsewhere on the Web. The files and folders in ~/Library are generally meant to be left alone, but if you’ve been using OS X for a while, chances are you’ve delved inside.

Inside your home folder is a Library folder-commonly written in Unix syntax as ~/Library, which means “a folder named Library at the root level of your home folder.” This folder is accessible only to you, and it’s used to store your personal settings, application-support files, and, in some cases, data.