Besides file comparison, this difference system can be a great deal of help if you wish to recover deleted files or folders. You just need to remember the name of the directory in which the deleted file was initially located. Will that relate to the problem? Yes, it will. If you view the local history of the folder, you will be able to see which actions have been performed on the directory.
The actions could be anything: new files or folders, a change in some of the files or folders, deletion of files or folders, and so on. You can now safely thank PhpStorm for monitoring each and every action you perform.
Once you find out the resource you were missing the most, you can revert to a timestamp that was just prior to the disastrous change.