A new site has launched today to help parents answer that question.

The site, run by the non-profit group Autism Speaks, is a unique video glossary that contains more than 100 clips.

The clips show children engaging in autistic behaviors, alongside videos of children without autism. The videos are supposed to help parents understand behaviors such as echolalia, hand flapping, sensory defensiveness and joint attention.

And the ultimate goal is to spark earlier diagnosis so children with autism can receive treatment as soon as possible.

Visit the video glossary here.