Child custody refers to which parent a child lives with and who has the right to make child-rearing decisions. In sole custody, the child lives with one parent who makes all the necessary decisions. However, it's not usually quite that simple. Custody actually consists of two separate concepts:
When one parent has sole physical custody, the child lives with that parent full-time. The non-custodial parent may have visitation rights, but the extent of visitation depends on the circumstances. A common arrangement is for the non-custodial parent to receive alternate weekends and dinner one night a week. A parent with a history of abuse or other problems may receive only a few hours of supervised visitation. Sole physical custody is common, as this provides the greatest stability for the child.
A parent with sole legal custody makes all child-rearing decisions, like schooling, medical care and religious upbringing. The non-custodial parent has no rights in the decision-making process. Courts have been moving away from awarding sole legal custody, and it is no longer common. It may be necessary if one parent is likely to harm the child or refuses to cooperate with the other, but the preference is to allow both parents to participate in a child's upbringing. Therefore, even when one parent has sole physical custody, the parents may share legal custody. In fact, the most common custody arrangement today is assigning primary physical custody to one parent but awarding joint legal custody to both.