Explain 'Branded Types' for Domain-Driven Design (DDD).

Branding simulates nominal typing by adding unique tags to primitives, preventing identical structures from being swapped[cite: 1].

Since TypeScript is structural, a UserId string and an AccountId string are interchangeable. Branding intersects a primitive with a unique object tag. While this tag is non-existent at runtime, the compiler treats them as distinct types, forcing developers to perform a validated cast before use[cite: 1].