Digital refers to a signal that consists of discrete states. A binary signal has only two states, 0 and 1.
Binary being base two numbers with only two possible values, 0, or 1. Primarily used by communication and computer systems.
"Digital" is in the NAICS Code "323115"
(Digital PrintingPrinting, digital (e.g., graphics, high resolution))
"Digital" is in the CPC Code "4523"