JPEG 
Joint Photographic Experts Group 
A format developed by the Joint Photographic Experts Group for storing and compressing high-quality color and grayscale images (.jpg file extension). JPEG files are usually small and relatively quick to download, but some image data is lost in the compression process. You can choose how much to compress a JPEG file, but the smaller you make it, the more color information is lost. (JPEG is pronounced "JAY-pehg.")