You will usually see digital cameras (and cameras built into mobile phones) advertised with the number of megapixels they capture highlighted. The higher the number, the better quality the image. 

Digital cameras capture images in tiny little blocks called ‘pixel elements’, or ‘pixels’. One megapixel simply means one million pixels. The higher the number, the more tiny blocks the image is broken into, the better the resolution. 

An image taken on a camera with too few megapixels may appear unclear when printed out, and can look fuzzy or ‘pixelated’ (blocky) when expanded or cropped too much