Metadata
Data that describes other data: who made it, when, where and what it contains.
Metadata is information about a piece of data rather than the data itself. A photo on your phone is the image, but it also carries the date it was taken, the place, the camera model and the file size. An email has a body, and also a sender, a recipient, a subject line and a timestamp. All of that is metadata.
In companies, metadata is what makes data usable. A table in a database is just rows and columns until something says what each column means, who owns the table, when it was last updated and where the numbers came from. Search engines, music apps and libraries all work the same way: they find things by their metadata, not by reading every file from scratch.
Metadata can also be sensitive on its own. Even without reading a single message, knowing who called whom, when and from where says a lot about a person. That is why privacy rules often cover metadata too, and why some apps strip the location from photos before you share them.
Keep in mind
- Describes data: author, date, size, format, origin, meaning.
- It is how search, catalogs and file systems find things quickly.
- In a company, good metadata is what lets people trust and reuse data.
- Metadata alone can reveal private details, so it deserves protection too.
