A stepparent is someone who becomes your parent through marriage, not through birth. When your mom or dad marries someone new, that person becomes your stepparent. If your dad marries someone, she becomes your stepmother. If your mom marries someone, he becomes your stepfather.

Stepparents join families that already exist, which can feel complicated at first. They don't replace your other parent. They're an additional adult in your life. Some kids live with a stepparent full-time, others see them only when visiting one parent. Every family figures out what works for them.

The relationship between stepparents and stepchildren varies enormously. Some stepparents become deeply important figures in a child's life, trusted and loved. Others remain more distant. Building these relationships takes time and patience from everyone involved.

You might also hear about stepbrothers and stepsisters, the children your stepparent brings into the family. Today, stepfamilies form for many reasons, most commonly after divorce.