This document discusses saving metadata to image files in Lightroom. Metadata contains information about photos like camera settings and edits made in Lightroom. By default, Lightroom saves metadata in its catalog file rather than the image files. Saving metadata to files protects edits if the catalog is lost or corrupted, and makes the files more forward compatible if opened in other programs. The process involves backing up images and catalog, selecting modified photos, and choosing Metadata > Save Metadata to File.