Definition
A living digital representation of a specific physical or operational system, connected closely enough to data about that system to support analysis, prediction, testing, or control. A twin is useful only within a stated fidelity boundary. It may reproduce the interfaces and behaviors relevant to one decision while omitting details that matter for another.
In an AI software factory, the target may be an external service rather than a machine. StrongDM's Digital Twin Universe uses behavioral replicas of services such as Okta, Jira, Slack, and Google Drive so agents can exercise realistic scenarios at high volume without changing production accounts. The replicas are evidence environments, not proof that every production behavior has been captured.
Where the term came from
Michael Grieves traces the modern concept to a 2002 product-lifecycle-management presentation. The model linked a physical product, a virtual counterpart, and the information flowing between them. Digital twin became the later name for that structure. Software teams now use the phrase more broadly, so a credible claim should name the real target, the synchronization mechanism, and the behaviors the twin is designed to preserve.
Distinguish it from nearby terms
A simulation can model a class of systems without corresponding to one specific operating instance. A test fixture supplies controlled inputs or state for a narrow test. An emulator reproduces an interface or platform. A digital twin claims an ongoing relationship with a particular target or environment. In practice these categories overlap, which makes the fidelity statement more useful than the label alone.
Check your understanding
Your payment-service twin reproduces successful charges but not delayed webhooks or provider rate limits. Can it justify an unattended release? Only for claims covered by the behavior it preserves. Record its known gaps, refresh cadence, data source, and the production evidence that still must be collected.