Autism spectrum disorder (ASD) is a neurological and developmental disorder that begins early in childhood and lasts throughout a person's life. Autism spectrum, also known as autism spectrum disorder (ASD), is a range of mental disorders of the neurodevelopmental type. It includes autism and Asperger syndrome. Individuals on the autistic spectrum often experience difficulties with social communication and interaction and may exhibit restricted, repetitive patterns of behavior, interests, or activities. It affects how a person acts and interacts with others, communicates, and learns. It includes what used to be known as Asperger syndrome and pervasive developmental disorders.