Identity refers to the qualities, beliefs, personality traits, appearance, and/or expressions that characterize a person or group.
In psychology, identity is the qualities, beliefs, etc. that make a particular person or group different from others.
The term "identity" also refers to:
1. The fact of being who or what a person or thing is
2. A close similarity or affinity
3. In mathematics, an equation that is satisfied for all values of the variables
4. In computing, the digital representation of a person's information