A first cousin is a relative who shares the same grandparents as you, and is the child of your parents sibling. First cousins are part of the same generational tier and are the same generation as each other. They are considered close family in terms of the law, and in the USA, they are often thought of like family for legal purposes to do with funerals and even commercial contracts. The child of your first cousin is your first cousin once removed, and you are also their first cousin once removed.