GAD vs AD NOS

I was recently diagnosed with "Anxiety Disorder, Not Otherwise Specified", assumedly because the psychiatrist had to write something in that little "diagnosis" box to justify the medication prescription. I am puzzled by something, though. What would lead to the decision of diagnosing "AD NOS" vs General Anxiety Disorder?
Put another way: how is the one distinquishable from the other? I have read the definitions of each, but was wondering if someone could state the differences in a very plain, non-jargon laden way? Thanks.

Ill be honest, I think pyschology divides fear/anxiety up into many little categories when really it is all just the same thing just manifesting in different ways. (OCD, Phobia, Gad) all anxiety/fear problems. So my point is, don't worry about what exactly "you have", just work on overcoming anxiety. You can do all things through Christ who strengthens you. Positive thinking , therapy, medication, the right attitude. All these things will help. You can do it

silachoo,

I do basically agree with you. Actually, I think much the same could be said for many other disorders of a given "type", not just anxiety disorders. It's the way these things manifest that separate them one from another. But see, this is exactly my question. In terms of signs and symptoms, what is the difference between GAD and AD NOS?