The Save command saves the current file to disk. The file is saved to its current name. Prior to saving, any changes you made to the current file were only present in the unsaved version you were editing. The file on disk never is changed until you save the file by using the Save, Save As, or Save All commands.
A file can also be saved by answering “Yes” to the “Save changes to file?” message when you try to close a changed file.
If the file is new and has never been saved before, or the file is read-only, then the Save command runs the Save As command instead. The Save As command allows you to specify the name of the file to be saved.