A camera exposure meter is a device that measures the amount of light in a scene to help photographers determine the correct exposure settings. It provides readings for shutter speed, aperture, and ISO, allowing users to achieve a well-exposed photograph. Exposure meters can be built into cameras or exist as handheld devices. These meters work by analyzing the light reflecting off subjects or the light falling onto them. By using an exposure meter, photographers can avoid underexposed or overexposed images, ensuring that their photos capture the intended details and mood.