One of Lion’s most impressive features is the new way that the OS handles the saving and managing of files. Versions and Resume allow the user to never have to worry about saving or losing files again — Lion just takes care of it.
If you still don’t really understand how Lion saves files, check out this infographic to see the process laid out in a simple way.
There are technically more steps involved, but the Lion does it all in the background. Apple knows how to do the dirty work so that the end user doesn’t have to worry about menial tasks, like saving files. What a thing of the past.