Although photography is ultimately about art, the use of high-tech gizmos inevitably leads to photographers throwing around an array of terms and acronyms that can be overwhelming to a new photographer. This list is (obviously) a work-in-progress, but I hope it’ll help a bit!
Canon's proprietary implementation of TTL flash control.
EXIF stands for "exchangeable image file format", which probably still doesn't help explain it much, but the idea is simple. Images you save in many well-known formats can embed non-image information in them. Typically, you'll see information like the date and time a photo was taken, the camera and (some) settings used to shoot it, and so on.
Any given image can have no EXIF information at all (if it's been stripped or removed) or lots and lots of it -- although the mechanism used to embed the information is a standard, the actual usage of it depends highly on camera manufacturers, photographers, editors, and anyone else who manipulates these files at any point in their workflow.
- Synonyms: exchangeable image file format