Autism is a biological condition that affects how a child, and later an adult, takes in information about people and the world. It is defined by difficulties understanding social communication accompanied by a need for sameness, sensory behaviors or repetitive actions, or thoughts. It is a huge spectrum. Like the different colors of a rainbow, autism affects different people in different ways. It often, but not always, occurs with other difficulties, including language delays, intellectual disability, ADHD, and sometimes mental health problems such as anxiety.