There is a long, controversial life to autism. Autism comes from the greek autos, meaning self. The term describes conditions which a person is removed from interaction — hence, an isolated self.
It was first described by a guy named Eugen Bleuler, a swiss psychologist who noticed the symptoms in a schizophrenic patient. Technically Autism is a particular diagnosis in the Autistic Spectrum which includes things like Asperger syndrome, there is even something called savant syndrome in which children display amazing abilities in a particular field [typically math or music] with no real training.