Save a Drawing
Save your drawing by clicking the Save button in the top-right. You can also use Ctrl (Windows) or ⌘ (Mac) +S.
Note: When you modify and save a drawing, it is saved in the AutoCAD 2018 file format, regardless of its original file format.
Save As
Save a drawing with a new name, or give a drawing a new file location by clicking the drop-down menu to the right of the Save button, and then choosing Save As. Alternatively, you can use the SAVE or SAVEAS commands.