A key characteristic that should apply to any useful model, including those created with UML, is that it abstracts away irrelevant details. This abstraction is crucial for managing complexity by focusing on the essential aspects of the system that are relevant to the current perspective or analysis task. By removing unnecessary information, the model remains understandable and manageable, even as the underlying system grows in complexity. This principle helps maintain a clear and concise representation of the system, enabling stakeholders to focus on strategic decisions without being overwhelmed by details.