Save and Compact

How does "Save and Compact" differ from "Save"? What does "Save and Compact" mean? Theses are both under the File menu. Sometimes I accidently click "Save and Compact" when I mean to click "Save," and nothing bad happens that I notice. But what is it doing?

DS

When you select Save and Compact, Flash creates a new optimized file (removing the undo history) and deletes the original file.

Caution: When you select Save and Compact, you cannot undo any changes you made before you saved the file. If you select Save when working with a document, you can undo prior to that save point. Because Save and Compact deletes the earlier version of the file and replaces it with the optimized version, you cannot undo earlier changes.


Info from http://www.adobe.com/devnet/flash/ar...ctices_02.html