Passive monitors are devices that observe and record data without actively interfering with the environment they are monitoring. They typically collect information such as temperature, humidity, or sound levels over time, providing valuable insights into conditions or behaviors without altering them. These monitors are often used in various fields, including environmental science, building management, and wildlife studies. For example, a passive acoustic monitor can capture sounds in a forest to study animal activity without disturbing their natural behavior. This unobtrusive approach allows for more accurate data collection and analysis.