An ego is a term used in psychology and philosophy to describe a persons sense of self or perception of their identity. It is the conscious part of a persons identity that they consider their "self". The ego can encompass a persons thoughts, beliefs, and self-worth, which may influence their behavior and interactions with others. It is essential to our very makeup and defines who we are and how we connect with others. However, when it becomes overpowering, it can lead to an inflated feeling of pride in ones superiority to others, which is known as egotism or self-importance.

The ego is not coextensive with either the personality or the body, although body concepts form the core of early experiences of self. It is capable of change throughout life, particularly under conditions of threat, illness, and significant changes in life circumstances. The ego comes to mediate between the superego and the id by building up what have been called defense mechanisms. A strong ego is exhibited in the following characteristics: objectivity in ones apprehension of the external world and in self-knowledge (insight); capacity to organize activities over longer time spans (allowing for the maintenance of relationships and the pursuit of long-term goals); and the ability to tolerate frustration and delay gratification.

In summary, an ego is a persons sense of self or perception of their identity, which can influence their behavior and interactions with others. It is essential to our very makeup, but when it becomes overpowering, it can lead to an inflated feeling of pride in ones superiority to others.