What is EXIF Data?
EXIF (Exchangeable Image File Format) is a standardised way of storing metadata inside digital image files. It holds technical information about how a photo was created — the date and time it was taken, the camera and lens used, and shooting settings such as shutter speed, ISO and aperture.
Beyond the standard fields every manufacturer uses, cameras also write manufacturer-specific EXIF fields for their own functions, so some of this data isn't shown by every piece of software.
EXIF isn't the only metadata in a photo. IPTC describes the content and rights — caption, keywords and copyright status — while XMP, developed by Adobe, is a more modern and flexible format that allows both standard and custom metadata. In short: EXIF stores the technical details, IPTC the content and rights, and XMP a flexible descriptive layer.