Personal identity refers to the concept of what makes an individual distinct from others over time. It encompasses various aspects such as memories, personality traits, and consciousness, which contribute to a person's sense of self. Philosophers like John Locke and David Hume have explored these ideas, questioning how identity persists despite changes in physical and psychological states. The study of personal identity also delves into the implications of identity in moral and legal contexts. Understanding personal identity is crucial for discussions about responsibility, autonomy, and the nature of the self, influencing fields such as psychology and sociology.