Step-siblings are children who become siblings through the marriage of one of their parents to someone who already has children. This means that they share a family connection, but they are not biologically related. Step-siblings often live together in the same household and may share experiences, responsibilities, and family traditions. The relationship between step-siblings can vary widely. Some may develop close bonds and treat each other like biological siblings, while others might struggle with feelings of rivalry or adjustment. Factors such as age, personality, and family dynamics can influence how step-siblings interact and form their relationships over time.