Which layer consists of cloud services, a B2B layer that holds all the commercial transactions, and a database server that supplies an organization's production data in a structured form (e.g., MS SQL Server, MySQL server)?

Which layer consists of cloud services, a B2B layer that holds all the commercial transactions, and a database server that supplies an organization's production data in a structured form (e.g., MS SQL Server, MySQL server)?

• A. The client or presentation layer
• B. The business logic layer
• C. web-server logic layer
• D. database layer

Answer: (D)

In a multi-tier architecture, the layer that stores and serves data is the database layer. This is where database servers like MS SQL Server or MySQL run and provide production data in a structured form to the rest of the application. Cloud services and the B2B layer may interact with this data, handle transactions, or provide access, but their primary role is to manage data flow and persistence. The other layers are about the user interface (presentation), applying business rules (business logic), or handling server-side logic, not about storing and delivering the actual data. Therefore, the described components fit the database layer.

In a multi-tier architecture, the layer that stores and serves data is the database layer. This is where database servers like MS SQL Server or MySQL run and provide production data in a structured form to the rest of the application. Cloud services and the B2B layer may interact with this data, handle transactions, or provide access, but their primary role is to manage data flow and persistence. The other layers are about the user interface (presentation), applying business rules (business logic), or handling server-side logic, not about storing and delivering the actual data. Therefore, the described components fit the database layer.