What's The Difference?

Mother and daughter are having a bonding moment. Daughter: Mommy can you differentiate the words terrible and horrible for me? Mother: Sure dear. Remember when we went to the beach last week? Daughter: Yes I remember. Mother: While swimming, your dad was caught by rip current. Daughter: Oh, that's terrible! Mother: That's right. Daughter: Mommy, what about horrible? Mother: The wave brought him back to shore.