The software architecture is a set of software components， subsystems， relationships， interactions， the properties of each of these elements， and the set of guiding principles that together constitute the fundamental properties and constraints of a software system or set of systems. （  ） defines a general set of element types and their interactions. The examples include Pipes and Filters， Model-View-Controller， and Reflection. A （  ） in software architecture is a representation used to understand or document one or more aspects of a problem or solution. Architecture is usually used in conjunction with many adjunct terms. The （  ）defines the key strategies， organization， goals and related processes of the enterprise. At the enterprise level， the （  ） may be more of a set of guidelines on how the various software architectures should be constructed consistently across the enterprise. The （  ）， which describes the high-level set of elements involved in application from a particular domain along with their interactions， is often used to focus on subsystem definition rather than application process level definition.