id, identity, entity definitions.

IDENTITY

 the distinct personality of an individual regarded as a persisting entity; "you can lose your identity when you join the army"

 the individual characteristics by which a thing or person is recognized or known; "geneticists only recently discovered the identity of the gene that causes it"; "it was too dark to determine his identity"; "she guessed the identity of his lover"

 an operator that leaves unchanged the element on which it operates; "the identity under numerical multiplication is 1"

 exact sameness; "they shared an identity of interests"
wordnet.princeton.edu/perl/webwn

Quality of identical. To be a person or thing the same one that is looked or is supposed.

www.definicion.org/diccionario/164

Identity: It is the personality of a people or human group, which makes it different of the others for his(its,her) values.

http://www.edufuturo.com/educacion.php?c=3359

Identity = Endless Path jointly

http://rita.lacoctelera.net/post/

ID

Id : It, I and Superyó or called Go, Ego and Superego, they are fundamental concepts in the theory of the psychoanalysis with which Sigmund Freud tried to explain how the mind works, suggesting that it has a particular structure. It supported that it is divided, to big features, in three intimately related parts: Go, the Ego and the Superego.

http://es.wikipedia.org/wiki/Id

Id : Habitually abbreviation of "identification". It is the "name" assigned to a user for the BBS or for a system in line, also named "UserName" (user's name) and "UserID" (user's identification) and serves to identify to the one who gets in the system. It can be a royal(real), name " name of war ", or a chain of characters generated and assigned by the local system.

http://www.monografias.com/trabajos22/diccionario-informatico/diccionario-informatico.shtml

- ID - (suffix) (descendant of ...).

http://www.diccionariosdigitales.net/glosarios%20y%20vocabularios/diccionario%20ido-castellano-iiiiii.htm

d. (Latin, short for "idem", "the same") is the term used in legal citations for the previously cited source (cf. ibid.). It is also used in academic citations where it replaces the name of a repeated author.
en.wikipedia.org/wiki/Id.

ENTITY

An entity is quite that one that exhibits:

·real EXISTENCE, not necessarily material or animated(inspired) Existence.

· Autonomy of management in its internal and external organization.

· Differentiation and individuality.

http://es.wikipedia.org/wiki/Entidad

Entity: It is the name or social reason with which it is known to public institutions and private road, national and international organisms and companies that are located exclusively in the Metropolitan District of Quito by its condition of the capital of the country.

http://www4.quito.gov.ec/spirales/8_diccionario_de_la_base_de_datos/8_7_administracion_y_capitalidad/8_7_2.html

ENTITY: In some conceptions of Theory of the Classification, category of the knowledge that includes all the entities or objects of a class. V.A. TYPOLOGY.

http://www.eubca.edu.uy/diccionario/letra_e.htm

A declaration that maps a name to some specific bit of information in XML. There are several kinds of entities: character entities, general entities, parameter entities, and system entities. An entity must be declared before it can be referenced.
www.sagehill.net/docbookxsl/glossary.html

Entity: Particular representation of resources of information, or response to a resource of service that can be included in a message of request or response. An entity consists of "goal - information" in the shape of head-boards of entity, and the content in the shape of body of entity.

http://www.ipm.com.pe/glosarionave.htm