ASD is a condition that affects the way a person relates to their environment. The word "spectrum" is used because not all people with autism have the same traits and difficulties. Some people find interacting more difficult than others. Autism may be very apparent in someone or they may show no outward signs of it. The main areas of difficulty are in social interaction, verbal and nonverbal communication and restricted or repetitive behaviors and interests. In most cases of autism, motor communication {doing things} is affected. All these signs develop in the child's first two to three years of age.