why does current slow down in a series than when in a parallel?

Answer 1

It does not slow down. Current travels at the same velocity.

Answer 2

why is it lower?

i have had conflicting views on it.

1) it stays the same because current is always the same

or

2) it is lower b/c there is a direct relationship btw current and voltage and in a parallel circuit, the voltage is higher so so must be the current