Acewell Dash confusion

[miniman1]

Hi guys, I'm installing an acewell dash to my bike but came across something I cant figure out.

On the dash wiring diagram, it has a wire labelled 'VDD'.

I cant figure out wot this is supposed to be for.

Any help???

[Fatgit]

Positive voltage supply connection.

[miniman1]

could anyone elaborate at all??