Can you tell me how exactly is autism classified, and what are its symptoms?

Autism: "several symptoms can be seen by 18 months of age, such as poor eye contact, trouble with pretend play and imitation, delayed communication skills and problems with "joint attention." joint attention occurs when a child points or otherwise tries to get someone to look at the same thing he is observing. Children with autism often don't point or show joint attention. www.autismweb.com. More info is at the site.It is now classified among the autism spectrum disorders.

Great link @ autism: Autism Speaks has a great website to learn about autism - everything from the basics of what is autism to very detailed information. Here is a good link: https://www.autismspeaks.org/what-autism/learn-signs BTW - there are so many great websites, not every one that has good info is by an excellent non-profit and not every non-profit gives good info.