Neurodiversity in simple terms is defined as a word to use to explain the unique ways a persons brain works.  Both Neurodivergent and Neurotypical brains exist in the Neurodiversity landscape.  

Neurodivergent people make up 20% of the global population and some experts put the number closer to 30-40%.  Well know types of Neurodivergence are but not limited to: ADHD, Autism, Dyscalculia, Dyslexia, Dyspraxia, Epilepsy, Hyperlexia, OCD, Tourettes, and Sensory Processing.