Identity is the state of having unique identifying characteristics that no other person or thing holds it. Identity is the individual characteristic which a person or thing is recognized by it. Identity defines a person as who he is and it is usually associated with labels for social positions or roles. Roles label is the meanings and expectations for behaviors that have evolved from countless interactions among people in a social system. They are externally defined by the expectations of others, but individuals define their own identities internally as they accept or reject social role expectations as a part of people who they are.
According to the social identity theory, social behavior exists from the spectrum of purely interpersonal to the purely intergroup where personal identity is salient. In such a context the individual will relate with others in an interpersonal manner depending on their character traits and personal relationship that exists between the individuals. Thus, under certain conditions social identity is more salient than personal identity in self-conception. Meanwhile, when this is the case and behavior is qualitatively different, it then becomes group behavior. Social identities are associated with normative rights, obligations and sanctions which within specific collectivities form roles. According to Giddens, Jary and Jary, identity is a sense of self that developed as the child differentiates from parents and family and took a place in the society. It refers to the sense that someone has of who they are, of what is most important about them. Important sources of identity are likely to include nationality, ethnicity, sexuality, class, etc.
Akerlof and Kranton, in economic sphere, incorporate social identity factor to principal agent model. Based on this, when the agent considers him an insider, the agent will maximize his identity utility by exerting high level effort comparable with his prescribed behavior. On the other side, if the agent considers himself an outsider, he will require a higher wage to compensate his loss for behavior different from prescribed behaviors. Therefore, the concept of identity is also closely related the idea of culture. Identity can be formed through the cultures and subcultures to which the person belong or in which he participates. However, different theories of identity view the relationship between culture and identity in rather different perspective. Those influenced by modern theories of culture are more likely to view identity as originating in a fairly straight forward way from involvement in particular culture and subculture. For instance, people living in Afghanistan would be expected to have a strong sense of Afghan identity.
Cultural identity is the identity of a group or culture of an individual and shows how An individual is influenced by belonging to that group or culture. A person is influenced by some factors such as ones religion, ancestry, skin color, language, class, education, profession, skill, family and politics etc., these factors contribute to the development of one’s identity. According to Elebeke,  it as a process located in the core of the individual and yet also in the core of his communal culture, a process which establishes, in fact the identity of these two identities.
Therefore, identity is inherent in all levels of human organizations namely personal, family, community, ethnic group, the local government, the state and the entire country as a whole. And everybody sees one another as brothers and sisters and therefore does almost everything in common in the context of the accepted identity. Identity forces and guides People structure and organize their lives to conform to the society’s way of life and cooperate to ensure the general progress of the society. When this happens they are seen to be identifying with their society. When we talk of national identity emphasis is no longer on identifying with the family, ethnic or religion, but on national identity as a belief in membership of a nation state. People in the contest of the national identity no longer look at themselves as belonging to any component unit within the country but consider themselves as belonging to the country (Afghanistan).
National identity is defined as the feeling of love and pride which a citizen has for his country. It is attitudinal in form and perceptual in content. The members of a country identify nationally when they are proud of their country and consequently are inward looking. According to Mamser, their attachment to and pride in the nation reflect their identification. Thus, in matters of national concern, citizens exhibit some measures of national identity. And when we talk of national integration we mean the development of an integrated and coherent national identity and consciousness in a multiethnic society like Afghanistan in which all citizens are given a fair opportunity to achieve their maximum potential. In such a contest, members are given sense of belonging irrespective of where they come from. Thus, national integration enhances the chances of creating higher loyalties that supersede parochial loyalties to ethnic cleavages. As a result, ethnicity and ethnocentrism with its attendant cultural differences, has been a great hindrance to this dream in Afghanistan. National integration in a multiethnic society like Afghanistan theoretically is a process of building a new society and social order based on justice and fair play to all its members no matter the ethnic group, language or religion an issue that has not been pursued with a strong and systematic political will in our country.
National identity is considered as social glue that integrates different members of the society regardless of their ethnicity, sexuality, class, etc. together. It can make the people feel of love and pride to their country. Meanwhile, it requires justice and fair play to all the members of the society by the government and all members of the society should be involved in all decision makings of the country and the government should have a strong political will to build a new society and social order.