Andrew Wasson of Creative Guitar goes over the two-hand tapping guitar technique. Tapping usually incorporates pull-offs or hammer-ons, where the fingers of the fretting hand will play a sequence of notes in synchronization with the other hand (tapping hand).
The technique is often associated with Eddie Van Halen and his songs "Erruption" and "Hot for Teacher." Although many other styles of guitarists use this technique (including Acoustic players) it is mostly considered and associated with Rock guitar. And, it is almost always seen performed on an electric guitar with distortion.