Metadata – Data describing data. An address list can contain a list of addresses. This list can have a name and the system storing it can record the list’s author, the date  on which it was written, the size of the list and its address on the storage device as well as the permission status of people who may access it. The name, author, date, size, address and permissions are metadata items, used in managing the address list and quite separate from the actual contents of the list.