A heuristic is a mental shortcut that helps people make decisions or solve problems quickly and efficiently. Instead of analyzing every detail, heuristics allow individuals to rely on past experiences or rules of thumb to reach conclusions. This approach can be useful in everyday situations, such as estimating time or making choices. However, while heuristics can speed up decision-making, they can also lead to biases or errors. For example, the availability heuristic causes people to judge the likelihood of events based on how easily examples come to mind. Understanding heuristics can improve critical thinking and decision-making skills.