metadata
Metadata refers to data about data.
It can be compared to the information about books in a library, where it is a small slip of paper with the book information (ISBN, publisher, author, edition), a small summary of the book, and the physical location of it.
Metadata helps you better understand some information as well as locate it — in time, in a physical or logical location, how many changes that information went through, etc.
Check Using properties in Obsidian.