JPEG has multiple meanings, all related to a compression standard for digitized photographic images. First, it is the acronym that stands for Joint Photographic Experts Group, the committee that created the JPEG standard. Commonly, JPEG usually refers to images compressed with the compression algorithm specified in JPEG standards. JPEG images are usually compressed using a lossy compression algorithm, but lossles JPEG compression is also specified. JPEG images most often have a .jpg file extension.