Co-parenting refers to a parenting situation where adults share the duties of parenting a child. Co-parents may include a variety of configurations, including a mother and a father, two mothers, two fathers, a parent with an adult sibling or grandparent, or a parent and another adult relative. The co-parent relationship differs from an intimate relationship between adults in that it focuses solely on the child. The equivalent term in evolutionary biology is biparental care, where parental investment is provided by both the mother and father.