In contrast to this is 'Low Function Autism' which refers to an individual who has less functionality in carrying out every day tasks.
Neither of these define an autistic individual's mental capacity toward emotional, cognitive, spacial, mathematical, abilities, only the individual's capacity toward carrying out "normal" activities such as personal care.
HFA is interchangable with Asperger's syndrome/disorder (after the discoverer, Hans Asperger; this is set to change in the DSM/V whereby the two may be merged into a single term, or diagnosing one will cease and only one of the two definitions will continue, unless Asperger's is differentiated from HFA (something which has yet to take place).
a form of alcoholism where the alcoholic is able to maintain their outside life such as jobs, academics, relationships etc. all while drinking alcoholically like a boss.
Friend: You should quit drinking.
Me: NONSENSE, I'm no quitter! I have a high paying job, an awesome girlfriend, and I graduated college with honors. I am an HFA.