Joint Photographic Experts Group (JPG/JPEG) and Portable Network Graphics (PNG) are two popular raster image formats being used over the internet. Unlike JPEG, which relies on DCT compression, the PNG uses LZW compression which is the same as used by GIF and TIFF formats. The biggest advantage of PNG over JPEG is that the compression is lossless, meaning there is no loss in quality each time it is opened and saved again.