A camera sensor is a device that detects light and converts it into electrical signals. It consists of an array of photodetectors, which are sensitive to light and generate an electrical current proportional to the amount of light they receive. The output from each photodetector is then converted into a digital value by an analog-to-digital converter (ADC), which represents the intensity of light captured at each point in the sensor array. This data is used to create an image, either as a still photograph or video footage.