The latest version of Mac OS X has a net function in most native apps. The ability to autosave a document. I think this is a great way as you always have the latest version of the document saved, this function also syncs with Time Machine so it save previous copies that you can return to. If, however, you don’t like this functionality, so want to revert to a more traditional way of saving documents, you can turn it off. It is a simple setting change, but like most setting within Mac OS X you have to know where to look.
Turning Off Auto-Save
To turn off auto save open up System Preferences. Select the General preference pane.
Half way down the list there will be an option to disable auto save. It is titled “Ask to keep changes when closing documents”. Enable this checkbox.
Now every time you make change in a TextEdit window, or other native app, it will ask you to save the change. The original functionality has been restored. You can, at any time, change this option by unchecking the box.