In
government, identity is a tool used to protect a person and his/her
constitutional rights. It proves you are, in fact, who you are. Don't let this recursive nature of identity scare you, it merely organizes individuals by means of their date and place of birth, and usually a number. In this sense, your identity is unique to every person legally recognized by said government, and can be used to obtain documents to further the priveledges of a person abiding the rules of said governmental constitution.
This "governmental" type of identity is also used in various private institutions as a means of populace organization. From the workplace, to a baseball park, Identity is perserved with various elements of proof. They include:
ID/membership (identification) cards or badges
ID/membership numbers
Biometrics
An entirely vague concept of identity refers to the unique mix of characteristics that comprise an individual. It is used to decipher cause and effect, subject and object, in an indifferent, continuous landscape that is reality. Identity is a formalisation of the patterns that define a person's behavior as they mature in life. It may have several parameters including:
Religiosity
Intelligence
Sociability
Sexual Preference
Self Esteem
Humor
Loyalty
Temper
Attitude
Creativity
Ambition