Autism spectrum disorder is a neurodevelopmental disorder, with the essential features being "persistent deficits in reciprocal social communication, in nonverbal communicative behaviors used for social interaction, and in developing, managing, and understanding relationships (Criterion A) and restricted, repetitive patterns of behavior, interests, or activities (Criterion B)." (DSM-V) Note that there is controversy around this definition because of the word "deficits" which indicates that Autism is a disorder that needs to be corrected whereas use of the word "differences" is the more friendly and acceptable term for people who see Autism as a neurodiversity.
Autism spectrum disorder now encompasses the following disorders that were once separate but related diagnoses:
DSM V: 299.0
According to the page linked above:
Inside the autism field and autism community, autism can be regarded in two main ways. The first is that autism is a disability and that efforts should be made to cure the disability. The second can be summarized by the neurodiversity movement, which is that autism is a neurological difference that should be regarded as any other human variance and celebrated as such. The controversy can be represented by the Autism Speaks logo and the neurodiversity symbol. Some in the autisitic community find that a puzzle does not accurately represent the experiences of those with autism, as they are not puzzles to be solved.