A more thorough explanation:

The Uniform Child Custody Jurisdiction Act (UCCJA) is a law created in 1968 that provides a standard for determining which state has jurisdiction over a child custody case. This is important because it helps prevent conflicting custody orders from different states and ensures that the best interests of the child are protected.

For example, if a child lives in California with their mother, but their father lives in New York and wants custody, the UCCJA would determine which state has the authority to make a custody decision. The UCCJA looks at factors such as the child's residence, connections to the state, and where the child has the most significant relationship.

The UCCJA was replaced in 1997 by the Uniform Child Custody Jurisdiction and Enforcement Act (UCCJEA), which provides more detailed guidelines for determining jurisdiction and enforcing custody orders across state lines.