Familiarity refers to the state of being well-acquainted with someone or something. It often develops through repeated exposure or experience, leading to a sense of comfort and recognition. For example, a person may feel familiarity with a friend after spending time together or with a city after visiting multiple times. In psychology, familiarity can influence decision-making and preferences. People tend to favor familiar items, such as brands or music, over unfamiliar ones. This phenomenon is known as the "mere exposure effect," where increased exposure to a stimulus enhances an individual's liking for it.