JPEG (.jpeg or .jpg) files follow the standards set by the Joint Photographic Experts Group. These files use a variable compression method that is called lossy compression because of the loss of image quality as you increase the compression. However, the JPEG compression scheme is extremely good and you can sometimes compress the file up to 200:1 without severe loss of image quality. JPEG is consequently a popular format for posting image files on the Internet for minimum file size and fast download time.
When JPEG is the chosen output format, clicking Render or Setup in the Render Output File dialog displays the JPEG Image Control dialog.