Identity formation, also known as individuation, is the development of the distinct personality of an individual regarded as a persisting entity (known as personal continuity) in a particular stage of life in which individual characteristics are possessed and by which a person is recognized or known (such as the establishment of a reputation). This process defines individuals to others and themselves. Pieces of the person's actual identity include a sense of continuity, a sense of uniqueness from others, and a sense of affiliation. Identity formation leads to a number of issues of personal identity and an identity where the individual has some sort of comprehension of him or herself as a discrete and separate entity. This may be through individuation whereby the undifferentiated individual tends to become unique, or undergoes stages through which differentiated facets of a person's life tend toward becoming a more indivisible whole.