Definition
Identity is the set of characteristics and information that allows a specific entity to be uniquely distinguished and recognised within a system or organisation.
Human Explanation
Identity describes who or what a user, device, application or service is and how it can be distinguished from others.
Why it Matters
Without a clearly defined Identity, secure Authentication, assignment of permissions and Access Control are not possible.
Conceptual Boundary
Identity alone does not grant the ability to use a system. It provides the basis for subsequent Authentication and Authorization.
Practical Perspective
Every access decision begins by establishing correctly who or what the system is dealing with.