What is Best Interests?

Legal Definition
Best interests or best interests of the child is a child rights principle, which derives from Article 3 of the UN Convention on the Rights of the Child, which says that “in all actions concerning children, whether undertaken by public or private social welfare institutions, courts of law, administrative authorities or legislative bodies, the best interests of the child shall be a primary consideration”. Assessing the best interests of a child means to evaluate and balance “all the elements necessary to make a decision in a specific situation for a specific individual child or group of children”.
-- Wikipedia