Under the File Menu there are items for Save and Save As. What's the difference and what does Save As do?
When a file has a name, using Save overwrites the existing file. It saves the new version of the file on your disk using the same name and location. This is often what you want to do. For example, if you have made corrections to a word processing document, you want to save only the version with the latest corrections. You don't want to save the older, incorrect version. Save accomplishes this.
You should save your file frequently while you are working on it. This will save you retyping and recreating your document if anything goes wrong with the computer. Always use save before Spell Checking and before Printing. Instead of always clicking on File, Save try the keyboard shortcut Command + S (hold down the Command Key and press S).
If a file does not have a name then there is no difference between Save and Save As. You essentially are in Save As even if you choose Save.
Save As lets you specify a:
Save As lets you specify a new name (if the file is unnamed) or another name (if the file has a name) for a file.
It also optionally lets you specify a location for the file to be saved. The location can be anywhere on your computer or the network.
Another option is to specify the format or type of the file, for example RTF or Word.
Use File, Save As when:
Save Your Files Frequently
Instead of always clicking on File, Save try the keyboard shortcut Command + S (hold down the Command Key and press S).