AI twin
An AI twin is a model of a specific real person, built from material that person supplied with explicit permission, used to produce writing, speech or images in their likeness. The defining constraints are consent to the source material, restriction to the person's own identity, and a deletion route that removes the underlying data.
AI twin is not AI avatar.
An AI avatar is a synthetic presenter that need not correspond to anybody real, so its only constraint is licensing the stock likeness. An AI twin is bound to one identified living person, which makes consent, scope and deletion part of the definition rather than a line in the terms of service.
In practice
The term exists because the older words describe the technology and not the arrangement. Voice cloning names a technique. Deepfake names a misuse. Neither tells you whose material was used, who is allowed to press the button, or what happens when that person changes their mind. An AI twin is defined by the answers to those questions rather than by the model architecture, which is broadly the same either way.
Consent is the load-bearing part, and it is worth being specific about what a serious implementation actually enforces. Repic's AI twin requires an explicit consent step before any voice or likeness material is accepted, so the permission exists in the same medium as the thing being licensed. It applies an own-voice-only rule: you may build a twin of yourself, and not of a colleague, a client, or a public figure whose clips you happen to have. Deletion removes the underlying data rather than hiding the feature, because a twin you cannot withdraw is not consented to, it was merely agreed to once.
The common misunderstanding is that a twin is primarily a scale device: ten times the output for none of the work. That is the least interesting use and the one most likely to embarrass you, because a twin trained on a thin sample and pointed at unfamiliar subject matter produces confident writing you would never have written. The reliable use is narrower and duller. A twin is good at carrying an already established voice across routine work, and poor at forming opinions you have not formed yourself.
Practically, treat a twin as a draft engine with your signature attached. Feed it material that genuinely represents how you write rather than only your best day, review everything before it goes out, and keep the line between sounds like me and is a claim I am making firmly on your side. If you are evaluating a provider, the useful questions are unglamorous: what exactly was consented to, can you see the enrolment record, is anything shared with other customers or used for training, and what is actually deleted when you leave. A provider that answers those in plain language is telling you more than any demo will.