[F-W-M]

> DDD is against the idea of having a single unified model; instead it divides a large system into bounded contexts, each of which have their own model.

If you have a large system it makes sense to divide it into smaller independent pieces. If you have a (micro)-service architecture you have distinct services, in a monolith you might have modules.

It is a hard problem to know where exactly the boundaries between services or modules should be, in any case DDD calls the things that make sense to decouple bounded contexts.