This paper is one in a series of papers published by the AIAA Digital Engineering Integration Committee (DEIC). Although the concept of the Digital Thread has been discussed and specific aspects of the Digital Thread are not new, this paper attempts to consolidate in one location a description representing the DEIC’s position on Digital Thread. The Digital Thread is central to the aerospace industry’s digital transformation. Put simply, the Digital Thread can be defined as the confluence of technologies and disciplines such as physics-based engineering modeling and simulation, artificial intelligence, big data, elastic cloud storage, and the internet of things (IoT) advance digital transformation in many sectors of the economy; however, their application is not sufficient for the digital transformation of the aerospace industry. In this context, digital transformation must impact decision making, and this is where the Digital Thread is foundational.