Answer
(a) downward
(b) right
Work Step by Step
(a) The graph of $y=f(x)-3$ is obtained from the graph of $y=f(x)$ by shifting __downward___ 3 units.
(b) The graph of $y=f(x-3)$ is obtained from the graph of $y=f(x)$ by shifting ___right___ 3 units.