RELATED: How to Reset Any Mac App to Its Default Settings
It’ll keep all your preferences from when you had it installed before. The preferences will still be available on your Mac, too - this is convenient if you’re uninstalling an app only to replace it with a newer version of the same app, or if you reinstall the app later down the line. Most of the time, these files will use very little space and won’t cause a problem. Erase an application and it will leave preference files left over in your Library folders. The above method doesn’t actually erase an application’s preferences. For example, try to move the Chess app to the trash and you’ll see a message saying, “Chess can’t be modified or deleted because it’s required by OS X.” How to Remove Left Behind Files Note that you can’t remove built-in applications by doing this. Uninstalling them will remove whatever system-wide changes they made. These applications were installed using the Mac package installer.
However, some applications will prompt you for a password when you try to move them to the trash.
