A heart rate monitor is a device that tracks your heart rate, or how many times your heart beats in a minute. It helps you understand how hard your heart is working during activities like exercise or rest. Many people use these monitors to improve their fitness levels or to keep an eye on their heart health. These monitors can come in various forms, such as wristbands, chest straps, or even built into smartwatches. By providing real-time data, a heart rate monitor can help you stay within your target heart rate zone, making workouts more effective and safe.