Welcome to Autodesk Forums!

Hi Esra,

Setting ISAVEBAK=0 will prevent AutoCAD from creating backup files on each save. And backup file is an exact copy of the drawing file prior to the last save.
If you have Autosave enabled in AutoCAD Preferences, then Autosave copy will be created regardless of ISAVEBAK settings. You can set Automatic Save time to low value and should be able to recover lost data from last Autosave file. By default Autosave files are in
/Users/YOUR_USER_NAME/Documents/Autodesk/Autosave
folder on your Mac.