In philosophy, identity has both metaphysical and logical uses.
Digital identity refers to the representation of identity in terms of digital information. A digital identity can be understood as the set of digital information that is attributable to any given entity. This entity may be human (an individual or a community), a physical object, or even digital information itself.
In the social sciences, identity has specific meanings, stemming from cognitive theory, sociology, politics, and psychology. See identity (social science).
For security systems, authentication identity refers to the characteristics that a person has that can be verified.