Here on the what is Autism Spectrum Disorder (ASD) page, you will see the Definition of what ASD is.
• It is a neurological pervasive developmental disorder
• Autism Spectrum Disorder is now one disorder with Specifiers, Modifiers, and 3 Levels of Severity.
These are part of an autism diagnosis. Instead of there being the 3 different labels for the same disorder such as Autism, Asperger's Syndrome, and pervasive developmental disorder not otherwise specified.