A metric is a quantitative measure used to evaluate and monitor the performance of an IoT system or device in real time. Metrics are used to collect data that can be analyzed to gain valuable insights into the behavior and effectiveness of the IoT device.

In an environmental monitoring system, metrics could include temperature, humidity, and air quality. In an asset tracking device, metrics could include the location, speed, and direction of the object in real time. These metrics are used to measure device performance and provide valuable information that can be used to improve its efficiency and effectiveness.