Executive functions enable children to pay attention, follow instructions, apply what they have learned, have those "aha!" moments in which they grasp how multiple facts interrelate, think of creative solutions, obey social norms such as waiting their turn and not butting in line or jumping out of their seat, mentally construct a plan, hold in mind what they did so they can understand how that relates to later consequences, and much more. One would be hard pressed to think of an aspect of life in which executive functions are not important. In this article, I define and explain executive functions and provide examples of how these sophisticated abilities manifest themselves even in infants. Finally, I explore how to support, train, and improve these critical skills.