The LEGO Group's number for one part in one colour. It is the number printed in the parts list of the instructions.
An element ID identifies a specific part in a specific colour, where a design ID names the shape alone. It is the number in the parts list at the back of a set's instructions. On a collectable minifigure bag, the run of digits printed beside the DataMatrix code begins with one, and you can type it into BrickDb's scanner.