An in-group is any group or category to which people feel they belong and with which they identify, often fostering a sense of loyalty, solidarity, and shared identity among its members. Membership in an in-group can be based on various factors such as shared ethnicity, nationality, religion, social class, occupation, or common interests. Individuals within an in-group often have a sense of "we-ness" and may view members of out-groups (those to whom they do not belong) as different or even oppositional. The distinction between in-groups and out-groups can play a significant role in social dynamics, influencing attitudes, behaviours, and intergroup relations, sometimes leading to in-group favouritism and out-group prejudice.