A more thorough explanation:

Sole custody is a legal arrangement that happens when parents of a child separate or divorce. It means that only one parent has the right to make important decisions about the child's welfare, health, and upbringing. This parent is called the custodial parent and they have physical custody of the child, which means the child lives with them most or all of the time. The other parent, called the noncustodial parent, usually has visitation rights that are determined by the court.

• A mother has sole custody of her child after a divorce. The father has visitation rights every other weekend.
• A father has sole custody of his child because the mother is unable to care for the child due to drug addiction.

These examples illustrate how sole custody works. In the first example, the mother has physical custody of the child and the right to make important decisions about the child's life. The father has visitation rights, but he does not have the same level of control over the child's life as the mother. In the second example, the father has sole custody because the mother is unable to care for the child. This means that the father has the right to make all decisions about the child's life without consulting the mother.