1 2 3 4 1 of 4 Digital images Graphics on a screen are made up of tiny blocks called pixels. The more pixels on the screen, the higher the resolution and the better the quality of the picture will be. The higher the image resolution, the more memory is needed to store the graphic. Image files can be either bitmaps or vectors. Bitmaps Bitmap images are widely used on digital cameras, smartphones and online. Common bitmap image file types include JPEG, GIF and PNG. Bitmaps are also known as pixelmaps or raster graphics.