I'd like to discuss briefly the jump smash, which is a little bit more advanced and requires a lot of timing. And as the term suggests, you're going to jump and smash at the same time.
The shot is identical to a regular smash except you're in the air while you're actually hitting the shuttle. And the purpose of this shot is to get more trajectory, more steepness when you're smashing downward. So you end up smashing closer to the front of the net instead of towards your opponent's body.
If you notice when Jeffrey is hitting the smash, he's striking the shuttle when he's at the peak height. And that's really important. Timing is very critical in the jump smash. If your timing is off you're going to mis-hit this shuttle and lose a lot of power, perhaps even completely mis-hit the shuttle.
So that's your basic jump smash.