Head Start is a program of the United States Department of Health and Human Services that provides comprehensive early childhood education, health, nutrition, and parent involvement services to low-income children and families. It is the oldest and largest program of its kind. The program's services and resources are designed to foster stable family relationships, enhance children's physical and emotional well-being, and establish an environment to develop strong cognitive skills. The transition from preschool to elementary school imposes diverse developmental challenges that include requiring the children to engage successfully with their peers outside the family network, adjust to the space of a classroom, and meet the expectations the school setting provides.