OS X Mountain Lion Bible

Saving Documents

After creating a new document, or while editing a document, you need to save your progress. Saving is an essential part of working with documents, committing the document you are working on—in its current state—to the disk. In the past, the burden to save was on you, but OS X Lion introduced the Auto Save feature, with which documents saved themselves automatically as you worked. Thus, most people now have some applications that save documents for them and some applications that still require users to save the contents manually.

For applications that don't automatically save their documents, I strongly advise you to save at periodical intervals to protect your work in case of any problems. To do so, make sure the document you are working on is in the currently active window, and save your progress by choosing File⇒Save or pressing +S. The Save command automatically updates the file on the disk with the contents of the new one.

Newer applications that automatically save documents still have a Save command. It's used with the Versions feature introduced in OS X Lion that lets documents keep track of all the changes you make to them, so you can revert to an earlier version easily, even in files that get moved or sent to other people. If an application supports this capability, every time you save the file, you're creating a new version within the document.

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