An analog sensor is a device that measures physical quantities and converts them into an electrical signal that varies continuously. These sensors can detect changes in temperature, light, pressure, and other environmental factors. The output signal is typically a voltage or current that corresponds to the measured value, allowing for real-time monitoring and data collection. Common examples of analog sensors include thermistors for temperature measurement and photodiodes for light detection. Unlike digital sensors, which provide discrete values, analog sensors offer a smooth range of outputs, making them suitable for applications that require precise measurements and continuous data flow.