There are three basic elements to slapping. One is to slap with the thumb of your right hand over the pickups. The second is to slap with multiple fingers of the left hand onto the strings over the fretboard. The third element is to pluck notes using available fingers on the right hand. Using these three elements to make a slap sound, you can combine them in any order to make whatever rhythms you want
Tapping is a technique where the right hand taps a string and alternates with notes played by the left hand
Sweep picking is combining fretting an arpeggio with the left hand and strumming slowly with the right