On the Mac, you can always hit Command-Z to undo something. You can also hit Command-Shift-Z to redo something and put it back to what it was before you hit undo. Make sense? This isn’t so easily done ...

If you use your computer often enough, you may be familiar with the feeling of making accidental mistakes on the keyboard, whether it be due to deleting a batch of text you didn’t mean to get rid of ...