Sensor (English name: transducer/sensor) is a kind of detection device, which can sense the measured information and transform the sensed information into electrical signals or other required forms of information output according to certain rules to meet the requirements of information transmission, processing, storage, display, recording and control.

The characteristics of sensors include miniaturization, digitization, intelligence, multifunction, systematization, and networking. It is the primary link to achieve automatic detection and control. The existence and development of sensors have provided objects with senses such as touch, taste, and smell, allowing them to gradually become alive. According to their basic sensing functions, they are generally divided into ten categories: thermal sensors, light sensors, gas sensors, force sensors, magnetic sensors, humidity sensors, acoustic sensors, radiation sensors, color sensors, and taste sensors.