Which of the following interaction types involves changing the system state?

The interaction type that involves changing the system state is indicated by the term "Commands." In the context of system operations and interactions, a command is a directive to perform a specific action that alters the state of the system or its resources. For instance, when a command is executed, it might create, update, or delete data within a system, effectively modifying its existing state.

This is a fundamental concept in various system design paradigms, such as command-query responsibility segregation (CQRS), where commands are used explicitly to invoke state changes, while queries are reserved for retrieving data without causing modifications. Commands trigger workflows and processes that result in a change, making them crucial for dynamic systems that react to inputs and perform operations leading to state transitions.

Other interaction types, such as queries and responses, are not primarily designed to alter the state of a system. Queries retrieve data without causing changes, while events typically signal occurrences that may or may not lead to a state change but do not themselves perform an action to alter the state directly. Thus, commands are distinctly characterized by their role in initiating changes in system state.