What defines an open system in the context of systems theory?

An open system in the context of systems theory is one that interacts with and is influenced by its external environment. This means it is not a self-contained or isolated unit; instead, it constantly exchanges information, resources, and energy with surrounding systems. The interaction allows the open system to adapt and respond to changes, inputs, or influences from the environment, which is a fundamental characteristic of this concept.

This feedback from the environment contributes to the system's ability to evolve, modify processes, and improve overall functionality. Open systems are essential in understanding dynamic environments, especially in healthcare, where patient needs, technological advancements, and regulatory changes demand continual adaptation and responsiveness.

In contrast, the other options describe systems that are either closed to external influences or do not adapt to environmental changes. For example, an isolated system lacks interaction with the environment, while a rigidly operating system cannot adjust or evolve, thereby limiting its effectiveness.