OS X incorporates a new function: Auto Save.
This function automatically records the history of a document as you create and make changes to it. OS X automatically creates a new version of a document each time you open it and every hour while you’re working on it. You can also create snapshots of a document whenever you like. This function keeps hourly versions for a day, daily versions for a month, and weekly versions for all previous months.
You can delete the versions history of your documents (Auto Save) from the Misc. tab of the Cleaning pane and from the Automation pane. This operation can cause some temporary issues with existing files that are locked or have saved states, even if file locking is turned off. Typically, this will be in the form of an alert message when using the file the first time, but it shouldn’t cause any serious issues.