Consider the following fragment of the conceptual model of an Architecture Description from ISO!IEC 42010:Which...

According to the conceptual model of architecture description from ISO/IEC 42010, an architecture view is a representation of a system from the perspective of a set of concerns. An architecture viewpoint is a specification of the conventions and rules for constructing and using an architecture view. A and B in the diagram correspond to these concepts respectively.

References: ISO/IEC/IEEE 42010: Conceptual Model1; ISO/IEC/IEEE 42010:2011 - Systems and software engineering — Architecture description2.