Designing the process control of a system is a complex task that often involves different people. A uniform understanding of the terminology is necessary for the successful, resource-saving implementation of the design. Therefore, this research aims at the definition and clarification of the key safety-related concepts, including robustness, flexibility, sensitivity, fault tolerance, resilience, and nonfragile control. We first examine the definitions in academic literature and then analyze their differences. We utilize process engineering simulation examples to provide an in-depth understanding of these distinctions. The significance of identifying and understanding the differences between these terms stems from their capacity to facilitate professional communication. Moreover, it makes it easier to deal with potential problems that might arise in real-world scenarios.