CMOS is an acronym for Complementary Metal Oxide Semiconductor. In the digital imaging industry, CMOS is also called an Active Pixel Sensor (APS), providing a digital photoreceptor on an integrated circuit. Essentially, the CMOS chip (or CMOS sensor) takes in light through the lens of the camera and converts it in to a digital image with individual pixel color sensors.

Having a strong CMOS sensor is critical to high quality photographs and video. However, in low-end digital equipment, it is typical for the lens on the device to be the main cause of issues with image quality compared to that of a higher-end device.

Because of the manufacturing process for the CMOS sensor, cameras with CMOS installed can be produced at a lower cost than comparable CCD sensors and provides the same or higher quality. The all-digital process provides quicker display on a preview screen of a digital camera.

Compared to the CCD image sensor, which is an analog photoreceptor that converts light in to an electrical charge which is then measured, a CMOS censor provides an all-digital image that uses less power and provides a faster display and image capture. Plus, it can be manufactured at a lower cost.