A step-sibling is a person who becomes a sibling through the marriage of one of their parents to another person's parent. This relationship does not involve blood ties, as step-siblings are not biologically related. Instead, they share a family connection due to the new family structure created by the marriage. Step-siblings often live together in the same household and may share experiences, responsibilities, and family traditions. Their relationship can vary widely, ranging from close friendships to distant acquaintances, depending on individual family dynamics and personal interactions.