Which type of sensor operates with only two positions?

A digital sensor operates with only two positions, typically representing binary states such as "on/off" or "high/low." This characteristic makes digital sensors ideal for applications where specific thresholds need to be monitored or where discrete data is necessary for control systems.

In contrast, an analog sensor provides a continuous range of values, which makes it suitable for applications that require measurements like temperature, pressure, or light intensity, where the precise measurement can fluctuate within a range. Both thermocouples and strain gauges also produce output signals that vary continuously rather than delivering just two states, further reinforcing the distinction between digital and analog sensors. Thus, the defining trait of digital sensors as operating in a binary format aligns perfectly with the requirements of the question.