They are very similar but would be used in differing contexts.
For example: "When I pushed the lever, it sent the balls into motion."
or "When he pressed the lever, there was a slight movement of the table and the balls rushed away."
Motion is what an object does. - 'The train was set in motion', 'the truck was in full motion' 'the ball was in motion.'
Movement is what people see - 'There was a movement behind the hedge' or 'I caught a movement out of the corner of my eye."