Autosave

Autosave is a feature in WordPress which automatically saves changes made to a post, page, or custom post type. It works on the Post Edit screen. Since version 3.6, WordPress also takes advantage of the local storage feature of the user’s browser so that changes can be saved even if a user loses internet connectivity. This feature is extremely important and useful because it prevents the risk of losing data. For example, if you were working on a post and your browser crashed all the sudden, then your work will not be lost (thanks to autosave).