Indicators are devices used to provide information about a certain system or process. The term 'indicators' can refer to two different types of devices: signals and DIALS. Signals are visual or auditory cues that indicate the status of a system or process, such as a traffic light or a bell. DIALS are physical devices with a pointer that indicates a numerical value, such as a speedometer or a thermometer. Both signals and DIALS are used to provide information about a system or process, making them indicators.