Definition - What does Legal Custody mean?
Legal custody refers to a parent's legal right to make decisions about the upbringing and well-being of their child or children. In cases of divorce, if the parents of a minor child have an acrimonious relationship, it is customary to provide legal terms for the specifics agreed between parties on how their children should be cared for and by whom. Legal custody differs from physical custody which lays out with which parent the child will live. Both types of custody may be shared between parents.
Justipedia explains Legal Custody
In cases where harmony is reached between parents post-breakup, joint legal custody is usually assigned. However, if parents tend to fight over every decision about a child's life, such as medical care, education, and religious instruction, a judge may assign sole legal custody or even assign one parent to be the "tie-breaker" in decisions in which the parents are unable to come to an agreement.