JPG — JPEG Image
JPG (or JPEG, for the Joint Photographic Experts Group that created it in 1992) is the world's most widely used photo format. It achieves small file sizes through lossy compression: it permanently discards visual detail the human eye is least likely to notice.
Every digital camera and phone shoots JPG (or its modern successor HEIC), and every device on earth displays it.
What JPG files are used for
- Photographs — the format was literally designed for them
- Web images where transparency isn't needed
- Email attachments and messaging, where size matters
Advantages
- Small files for photographic content
- Universal compatibility — the safest image format to send anyone
- Adjustable quality/size trade-off
Limitations
- Lossy: every re-save at lower quality degrades the image further
- No transparency support
- Poor at sharp edges — text and flat graphics get visible artifacts
- EXIF metadata can leak location and device details if not stripped
How to open a JPG file
Everything opens JPG files — browsers, photo viewers, editors, office software. The more common tasks are converting: to PNG for lossless editing, or to WEBP for smaller web-ready files.