Social identity refers to the way individuals define themselves in relation to the groups they are a part of, such as nationality, ethnicity, or religion. This concept plays a crucial role in shaping our self-esteem and influences our interactions with others, as we often seek to align ourselves with groups that reflect our values and beliefs. The theory of social identity suggests that people categorize themselves and others into various social groups, which can lead to in-group favoritism and out-group discrimination. Understanding social identity helps us comprehend social dynamics and the impact of group membership on behavior and attitudes.