Child development is the series of changes a child makes from the time they are born until the time they complete adolescence and become young adults. These changes are physical, mental, emotional, and intellectual. While every child develops differently, the ultimate goal at the end of the child development period is for the person to become independent and no longer need their parents or caregivers for survival in society. This involves developing problem-solving skills, learning self-control, understanding how to interact with others, using new speech and language skills, developing fine and gross motor skills, and mastering sensory awareness.

Genetics, environmental factors, prenatal events, access to education and various stimuli, a child's learning capacity, and medical diagnoses can all impact child development, both positively and negatively. In the professional world, child development is often divided into three stages: early childhood (birth to around age six), middle childhood (around age six to around age twelve or the start of puberty), and adolescence (around age twelve until around age eighteen). Those who work in the field may specialize in one age group.‎

Children born today are the key to keeping society running in the future, so understanding child development and supporting those children to ensure they hit their developmental milestones is important to almost every person. Whether you're a parent, a caregiver, or someone who works with children on a professional level, learning about child development helps you make a positive impact. If a child isn't progressing the way he or she should, you can intervene and attempt to correct it. Specific courses, certifications, and degrees may also help you advance your career.‎

Any career that involves children must understand child development on some level. Teachers, educators, and administrators, from preschool through high school, use this information on a daily basis. Those who work in child care, such as daycare workers, nannies, and babysitters use child development. In the medical field, therapists, counselors, pediatricians, and pediatric nurses create a plan of care based on developmental milestones. Other careers include social work, manufacturing and retail of children's products, communications—including those who write and develop children's books and television programs—community service careers, and case managers.‎