A pixel (short for picture element) is the graphical representation of a single point in a image. In a photograph, it is the smallest unique element. If you zoom in closer and closer to a digital picture or satellite image, the image will appear more and more grainy, and you will begin to see individual boxes. Each of these boxes is a pixel.
Pixels are important in geospatial technologies in raster images and in remote sensing products. A pixel defines the smallest unit of area in an image or raster data set and determines its maximum spatial resolution. Pixels, which typically are squares, represent a square area on the Earth.
When we state that an image has a pixel resolution of 1 meter, we mean that each pixel represents a square area 1 meter on each side; a 30-meter resolution image has pixels that are 30 meters on each side, and each pixel covers 900 square meters. Generally speaking, the smaller the pixel size, the greater the detail that can be captured and stored in an image.
