Customer AI is part of Intelligent Services. It helps predict what a customer is likely to do. See the documentation.
Customer AI allows brands to create churn or conversion machine learning based scores that will be available as profile attributes in the Adobe Experience Platform profiles (Real-time Customer Profile).
As a result, they can be used as any other profile attributes in Journey Orchestration’s conditions (to make the best decisions), actions or segment building.
Note that Customer AI is a paid feature of the Adobe Experience Platform.