A camera's resolution is usually defined as the number of megapixels (or millions of pixels) that it can capture in a single photo. This is obviously a pixel-count resolution. Most digital cameras capture images on a CCD (charge coupled device) sensor. The camera's resolution is calculated by multiplying the number of pixels along the length and width of the sensor. Contemporary cameras typically capture between one million and six million pixels per image.
A two-megapixel camera, operating at maximum resolution, will create an image that has about two million pixels. However, most cameras offer at least three different pixel-count settings for taking pictures with varying degrees of quality. These numbers are expressed in terms of pixel dimensions such as 1600 x 1200 or 800 x 600. At lower settings, the camera captures fewer pixels to create a smaller image that requires fewer bytes to store in memory.