Contextuality refers to the idea that the outcome of a measurement or observation can depend on the context in which it is made. In quantum mechanics, this means that the results of experiments can vary based on the specific conditions or other measurements being performed simultaneously. This challenges classical notions of reality, where properties are thought to exist independently of observation. In practical terms, contextuality suggests that understanding a phenomenon requires considering the surrounding circumstances and relationships. For example, in psychology, a person's behavior may change based on their environment or social interactions, highlighting the importance of context in interpreting actions and outcomes.