In more detail
EXIF sits in a segment of the JPEG, separate from the pixels, so it can be edited or removed without changing the picture. It is useful for photographers and investigators but is a privacy risk when pictures are shared with the location still inside. See How EXIF Photo Metadata Works. Technically it is a small TIFF structure stored in the JPEG's APP1 segment (marker FF E1), starting with Exif\0\0 and a byte-order mark (II little-endian or MM big-endian). Typical tags are camera make and model, date taken, exposure, lens, orientation and a GPS block with the Geotag. HEIC, PNG and WebP can carry EXIF too.
Why it matters
Many social networks strip EXIF on upload, but email attachments, messaging apps set to send "original quality", cloud links and website uploads often keep it. Investigators, conversely, treat EXIF as a lead rather than proof: any field can be edited, and a missing block may only mean the file was re-saved.
Example
A JPEG made for this page, as identified by file and its first EXIF bytes at offset 20:
$ file a.jpg
a.jpg: JPEG image data, JFIF standard 1.01, ... Exif Standard: [TIFF image data,
big-endian, direntries=4, manufacturer=ExampleCam, model=Model X,
datetime=2026:07:14 15:42:10, GPS-Data], baseline, precision 8, 64x48
00000014: ffe1 00d4 4578 6966 0000 4d4d 002a
FF E1 opens APP1, 00 D4 is its length (212 bytes), then Exif\0\0 and MM 00 2A (big-endian TIFF). Remove such data with the EXIF Metadata Remover.