Explain the concept of dependency direction in the principles of clean architecture.

In clean architecture, the direction of dependencies means that dependencies always point inward, from outer layers to inner layers.

This means that:

• Inner layers (e.g., business logic) do not depend on outer layers (e.g., UI, database).
• Outer layers can depend on inner layers, but not vice versa.
• Interfaces and abstractions are defined in inner layers, and outer layers implement these interfaces.

This approach ensures that business logic is independent of implementation details, simplifying testing and maintenance of the code.