A heuristic, or rule of thumb, is a simple, practical approach to problem-solving or decision-making that helps individuals make quick judgments without extensive analysis. Heuristics are often based on experience and can lead to satisfactory solutions, especially in complex situations where time or information is limited. These mental shortcuts can sometimes lead to biases or errors, but they are useful in everyday life. For example, the availability heuristic allows people to assess the likelihood of events based on how easily examples come to mind, influencing their perceptions and choices in various scenarios.