If you’re working on a document and you want to preserve the original use the save as shortcut. This will leave the original file as it was last saved and create a new version which you are working on. It’s easy to remember because it’s basically the save shortcut with the shift modifier.
When you choose save as a dialogue box will popup to allow you to choose your directory and file name. Some applications will give you the option to save a copy or overwrite the original. The save-as shortcut is not to be confused with ‘save a copy’ shortcut, effectively they do the same thing but ‘save a copy’ will save the file in that state and let you carry on working on the unsized original. So, you’ll have 2 versions of the file. One file closed and preserved in that current state, and another file open that you’re working free to mess up like your worse pear of pants!
If you’re looking for a way to get your colleagues to kick the crap out of you do this. When opening a file that you intend to keep an original copy of accidentally press save instead of save as. You’ll carry on working for hours without realising you’ve overwritten the original document. At best you’ll have a backup somewhere and you may get away with a slap. At worst your colleague will have to correct everything you’ve done to restore the original before stapling you to the ceiling naked. Be mindful of the save, save as, save a copy mixup minefield. Everyone’s fallen foul of it and been the office dickhead.