CBR, or Case-Based Reasoning, is a problem-solving approach that uses past experiences to inform current decisions. It involves storing and retrieving cases, which are specific instances of problems and their solutions. When faced with a new problem, CBR systems compare it to similar past cases to find the best solution. This method is widely used in various fields, including artificial intelligence, medical diagnosis, and customer support. By leveraging historical data, CBR can improve efficiency and accuracy in decision-making, making it a valuable tool for professionals seeking to solve complex issues based on previous outcomes.