What IPTC metadata is
IPTC metadata is the industry-standard schema for the descriptive information stored inside a photograph. Named after the International Press Telecommunications Council, which defined it for the news industry, it gives every image a consistent place to hold its caption, the photographer’s credit, copyright and usage terms, keywords and other context.
The point of IPTC fields is that they are embedded in the file itself, not held in a separate document. Professional tools read and write them, so the caption and credit stay attached to a publicity still as it is copied, renamed and passed between photographer, publicist, picture desk and publishing platform. This is what makes a captioned image discoverable and correctly attributed rather than an anonymous JPG.
IPTC is one part of a file’s wider image metadata, and embedding it is a standard step before a stills set is delivered. For how to write and apply captions in practice, read our guide to captioning film and TV stills.