JPG is a file extension for a lossy graphics file. The JPEG file extension is used interchangeably with JPG. JPEG stands for Joint Photographic Experts Group who created the standard. JPG files have 2 sub-formats, JPG/Exif (often used in digital cameras and photographic equipment), and JPG/JFIF (often used on the World Wide Web).
The JPEG standard specifies the codec, which defines how an image is compressed into a stream of bytes and decompressed back into an image, but not the file format used to contain that stream. The Exif and JFIF standards define the commonly used formats for interchange of JPEG-compressed images.
A JPG file consists of a sequence of segments, each beginning with a marker, each of which begins with a 0xFF byte followed by a byte indicating what kind of marker it is. Some markers consist of just those two bytes; others are followed by two bytes indicating the length of marker-specific payload data that follows.
JPG files can be opened by most image editing software, from Microsoft Paint to Adobe Photoshop.
MIME type: image/jpeg
Learn more about .JPG files:
Visit theJPEG web page.
See answers to .JPG-related questions at ITKnowledgeExchange.com.