A heart rate monitor is a device that tracks your heart rate, which is the number of times your heart beats per minute. These monitors can be worn on the wrist, chest, or even as a smartwatch feature. They are commonly used during exercise to help individuals maintain their target heart rate for effective workouts. Heart rate monitors work by using sensors to detect blood flow and measure the heart's electrical signals. This information can help users understand their fitness levels, manage their health, and improve their performance in activities like running, cycling, or other sports.