Camera exposure refers to the amount of light that reaches the camera's sensor or film when taking a photograph. It is determined by three main factors: aperture, shutter speed, and ISO. The right balance of these elements ensures that an image is neither too bright nor too dark. Aperture controls the size of the lens opening, affecting depth of field, while shutter speed determines how long the sensor is exposed to light. ISO measures the sensor's sensitivity to light. Adjusting these settings allows photographers to achieve the desired exposure for different lighting conditions.