Which components belong to the SAP application layer?

The SAP application layer consists of components that are responsible for processing business logic and managing communication between users and the database. In this context, the correct option refers to the components that cater specifically to application-level functions within the SAP architecture.

The Database interface is a crucial component in this layer as it handles communication between the application and the database, facilitating the execution of queries and the retrieval of data needed for application processing. It translates high-level database operations into a format that can be understood by the database management system, thereby enabling effective interaction between the application and the data.

In this scenario, other options may not fit the definition of the application layer. The Database server pertains to the database layer, where the data is actually stored and managed, while SAP GUI serves as the graphical user interface for users to interact with the SAP system, but it does not process the business logic itself. The ABAP dispatcher manages the distribution of work among various application servers but is part of the overall application server architecture rather than solely the application layer.

Therefore, focusing on the specific role and function within the application layer confirms that the Database interface is the component that rightly belongs to this layer.