“Traces the information left the sensors on your computer”
Apple computers carry inside all sorts of sensors, from measuring the temperatures of the CPU or battery until the voltage of the latter, motion sensors and supplies, fans, etc.
Hardware Monitor is an open window on these sensors, harvesting data about each and showing it with multiple views: list, windows with detailed or colorful graphics and configurable information. Not only harvest information but includes a warning system in case, for example, the temperature of your battery or fan stops operating is exceeded.
Notices may be notifications in the Dock, from the menu bar on the desktop or vocally. Hardware Monitor is the ally of all who coddle your computer because it can be a good source of information if a possible diagnose and locate problems.