Exceptional children are those who significantly deviate from the norm in physical, mental, social, or emotional aspects, including gifted children (IQ above 130) and creative children who produce new ideas. Slow learners have an IQ above 70 but learn at a reduced rate, while underachievers consistently perform below their potential. Other categories mentioned include mentally retarded children (IQ below 70), physically handicapped children, and socially/culturally disadvantaged children.