JPEG is a file extension for a compressed raster graphics file format as standardized by the Joint Photographic Experts Group (also known as JPEG). JPEG is sometimes abbreviated asJPG for compatibility with older operating systems.JPEG is a 24-bit, 16.7 million color supporting file and is a lossy file compression that allows the user to adjust the ratio of compression based on the desired quality or file size. JPEG is one of the most common image file types on the World Wide Web.