metadata
Information that describes and gives details about other information.
Metadata is information about information. When you take a photo with a camera or phone, the image itself is the main information, but hidden details get recorded too: the date and time, the camera settings, maybe even the location. Those hidden details are the metadata.
Think of metadata like the label on a file folder. The folder contains the actual documents, but the label tells you what's inside, when it was created, and who it belongs to. In a library, a book's metadata includes its title, author, publication date, and subject, all recorded in the catalog so people can find it. The book itself contains the story or information, but the metadata helps organize and locate it.
Digital files have tons of metadata. A music file stores the song itself, but also the artist's name, album title, track number, and length. When you search for songs by a specific artist, you're actually searching the metadata, not listening to every song. Word documents can track who created them and when they were last edited. Photos from your phone might record which direction you were facing and what model phone took the picture.
Metadata helps computers organize millions of files and helps people find exactly what they need without opening everything to look inside.