A discussion on digital twins in nondestructive testing begins with the history of digital twin technology. Starting as a lifecycle management tool with the name coined by NASA, digital twins quickly grew. Several key factors restrict digital twin technology from being classified as an emerging technology. These factors include radical novelty, definition agreement, and applicable impacts. The path towards enabling digital twin technology to be defined as an emerging technology starts with a comparison of the various definitions of digital twins across industries. The definitions break out into two main schools of thought. The first school of thought is the original lifecycle management tool definition called the Vickers/Grieves digital twin. The second school of thought comes from the National Academies of Sciences, Engineering, and Medicine (NASEM) digital twins which addresses the factors restricting digital twin technology. Differences in the schools of thought and the applicability to nondestructive testing are demonstrated in the comparisons of their respective typology. This comparison establishes that the NASEM school of thought is best suited for digital twin technology to become an emerging technology in nondestructive testing. Further expansion on the NASEM digital twin identifies the importance of verification, validation, and uncertainty quantification (VVUQ). VVUQ is critically important in nondestructive testing digital twins where quantified uncertainty is a normal qualification measure for an inspection. Various common methods of nondestructive testing are presented with application to the typology of NASEM digital twins. This study concludes with a proposed nondestructive testing specific definition based on the formal NASEM definition.