This operation is a convenient form of modifying a file and saving it again in the same CIFKM location. It will automatically be sent again to the same place in CIFKM replacing the old file. The old file will be preserved as an older version of it, that may be recovered using the history (or the menu option) button.
However, if one is going to make many changes in the document, for example, if one is going to remake a new version, and during this work, one is going to save many times, we then recommend downloading it and making the changes outside CIFKM. Once completed, it may be drag and dropped in its CIFKM site replacing the old version.