Identity refers to the distinctive characteristics of a person's character or the character of a group which relate to who they are and what is meaningful to them, providing a sense of self and belonging. Some of the main sources of identity include gender, encompassing social expectations of masculinity and femininity; sexual orientation, referring to patterns of emotional, romantic, and sexual attraction; nationality or ethnicity, based on shared cultural heritage, origin, and often language or religion; and social class, reflecting one's position in the socioeconomic hierarchy. Identity is not fixed but is fluid and can evolve over an individual's life course through interactions with others and within different social contexts. It shapes how individuals perceive themselves and how they are perceived by others, influencing their social interactions, opportunities, and experiences within society.