What is the difference between attention-deficit/hyperactivity disorder and asperger's?

Different disorders. Adhd refers to problems with attention, impulsivity, and/or hyperactivity. "executive" functions are not as well developed as they should be. Asperger's falls in the autism spectrum. Asperger's symptoms include poor social skills, odd communication style (sing-song like speech), difficulty with changes in routines, preoccupations, and heightened sensitivity to sights and sounds.
Aspergers. Aspergers is a over connected mind. Adhd is more of an issue related to executive function and transitions. Many aspies are also adhd but seek out a licensed psychologist to clarify. Here is a video about aspergers that may be informative. Aspergers in 8 mins. http://youtu.be/xg1ngp1ngds.