A brother or sister is a sibling, meaning they share at least one biological or legal parent. Siblings often grow up together, sharing experiences, memories, and sometimes conflicts. They can provide companionship and support throughout life, contributing to each other's social and emotional development. The relationship between brothers and sisters can vary widely. Some siblings are very close and share a strong bond, while others may have a more distant relationship. Factors such as age difference, personality, and family dynamics can influence how siblings interact with each other. Siblings can also play important roles in each other's lives as they grow older.