Sensors provide an output signal in response to a physical, chemical, or biological measure and typically require an electrical input to operate them; therefore, they tend to be characterized in specifications in much the same way as electronic devices are characterized. To truly understand sensors, and how sensors that measure the same measure and differ, it is necessary to understand sensor performance characteristics. There is no standard definition for many of these characteristics and different parts of the sensor community have different names for these characteristics, depending on the sensing domain. This paper describes these characteristics, using their most common names and reference alternative names, where relevant.