A more thorough explanation:

The Uniform Child Custody Jurisdiction and Enforcement Act (UCCJEA) is a law that has been adopted by every state in the United States except for Massachusetts and Vermont. It is used to enforce child custody judgments across state lines and prevent forum shopping, which is when someone tries to get a more favorable custody award by filing in a different state.

The UCCJEA provides a way to obtain and enforce custody and visitation orders across state lines. It also protects children who are victims of abuse or domestic violence.

For example, let's say that a couple gets divorced in California and the mother is awarded custody of their child. The father moves to New York and tries to get custody there because he thinks he will get a better outcome. The UCCJEA prevents this by requiring that the custody case be heard in California, where the original custody order was issued.

Another example is if a mother and father live in different states and have a custody agreement. If the mother moves to a different state and violates the custody agreement, the UCCJEA allows the father to enforce the agreement in the state where the mother moved to.

These examples show how the UCCJEA helps to prevent forum shopping and ensures that custody and visitation orders are enforced across state lines.