Slapping the bass is a derogatory term of playing the bass guitar using a "slap" manoeuvre. Commonly used by Davie504, an Italian bass playing youtuber.
The technique is used by many famous bass players, such as Flea.
A technique of playing bass, commonly used by Funk bassists and reggae bassists.
It is played with the fingers, and is used to create a popping sound from the string hitting the pickups. The player usually plucks less than the average bassist, and rather uses hammer ons and pull offs
Flea is usually known as the best bassist ever, because he plays slap bass instead of picking.