A sister is a female sibling, typically sharing at least one biological or legal parent with another person. Sisters can have various relationships, ranging from close companionship to rivalry. They often grow up together, sharing experiences, memories, and family traditions. Sisters can also play significant roles in each other's lives, providing emotional support and guidance. In many cultures, the bond between sisters is celebrated through various customs and rituals. The relationship can evolve over time, often becoming stronger as they mature and navigate life's challenges together.