Did you know that your Mac keeps older versions of the documents you work on, auto-saving them in the background so you can go back to a previous revision, any time you like? It’s just like Time Machine, Apple’s Mac backup feature, only it’s for individual files. It even lets you compare old and current versions of your file, side-by-side. It’s called file versioning, and it’s pretty rad.
How to browse all the auto-saved versions of your Mac documents

Photo: Marta Miguel Martínez-Soria/Flickr CC