Good question!
A definition of Autism that we like, by Julia Leatherland
“Autistic individuals share a neurological type, which is qualitatively different to that of non-autistics, and which will necessarily impact, both positively and negatively, on aspects of their thinking and learning; sensory processing; social relational experiences; and communicative style, abilities and preferences. An autistic person’s experience of and ability to be successful in the world, will be dependent on the closeness of compatibility, between their individual profile of skills and requirements and their physical and social environment. Levels of sensitivity to environmental factors vary between individuals, and within the same individual over time, so that the presentation of autism is ever changing. A person’s neurological type, however, remains constant, and being autistic is a lifelong identity.”
DIALOGICA - Creators of Autism Dialogue 