What defines the structure of IT systems and their components?

Systems architecture is the framework that defines the structure, behavior, and interactions of various components within an information technology (IT) system. It encompasses the organization of the system's hardware and software, and how these components interact to fulfill the system's intended functions. This encompasses aspects such as the choice of technology, system design, and communication patterns between parts of the system.

In the context of IT systems, systems architecture serves as a blueprint that guides both the development and the operation of the system, ensuring that it meets user requirements, integrates well with other systems, and is scalable to accommodate future needs. A well-defined architecture can lead to improved performance, easier maintenance, and a clearer understanding of how the components work together.

In contrast, GIS software refers to specific applications designed for geographic data analysis and visualization, which is just one aspect of IT systems. Application development methods concern the processes and methodologies used to create software, which are important but do not define the underlying structure of the systems themselves. Geospatial Core Technical Knowledge encompasses a broader range of knowledge related to GIS but does not specifically address the structural aspect of IT systems.