An analytical model design with a fact table in the center, storing measurable values (amounts, quantities), and dimension tables around it, with descriptive attributes (product, customer, date), joined by one-to-many relationships.
In DP-900 it is used for data warehouses and is the design Microsoft recommends for Power BI models, because it improves performance and simplifies DAX measures.
Star schema is a concept that can show up on the exam. Check the full guide to see it in context.