Nowadays electronic drums are more sophisticated than ever, and can prove to be an invaluable tool in the studio. Essentially, they are a controller, sending data about which pad has been struck and how hard, to a ‘brain’ which then triggers a sample. However, the really cool thing about them, is that the data in question can be stored as MIDI data, and recorded into your DAW, allowing you to capture the drummers performance, which can then be edited and applied to different sample sets later, at your leisure.
But aside from all that, the main advantage is that you can whack the living daylights out of them, and disturb no-one! In your headphones it can sound like the wrath of God, but outside all that will be heard is the clickety clack of your sticks on the pad surface.