What is the function of the 'Extension' model in Dynamics 365?

The 'Extension' model in Dynamics 365 serves the primary purpose of encapsulating custom business logic and UI elements. This model is fundamental as it allows developers to extend the capabilities of the standard application without modifying the original codebase. By doing so, customization can be achieved in a way that is maintainable and compatible with future updates.

Using the Extension model enables developers to create new functionality, enhance existing processes, and tailor the user interface to better meet specific business needs. This approach not only provides flexibility but also ensures that updates to the core application can be applied seamlessly, without breaking any customizations. Thus, the Extension model plays a critical role in enabling organizations to adapt Dynamics 365 to their unique requirements while maintaining a robust and upgradeable system structure.