GUID is an acronym for 'Globally Unique Identifier'. A GUID is also sometimes called a UUID or 'Universally Unique Identifier. A GUID/UUID is a globally unique ID (string) that identifies a digital entity (person, place, or thing) that needs to be managed and kept available for a length of time. GUIDs are being assigned to research data, research publications, people, organizations, grants, laboratories, and a growing number of places and things.