Those statements are not necessarily in contradiction. When I quickly move the mouse in a circle on my computer I see the pointer displayed at several, quite far away, locations at the same time. It looks like the same time anyway because of temporal fusion.
If the mouse were moving continuously you would be able to see the full trace of its path and not just a few discrete locations along the way. A higher frequency would get closer to this.
Also, in an interactive scenario, the frame rate will impact how quick you get feedback on your actions.
With 60Hz, the frames each take 17ms, meaning the next frame will be on average 8.3 ms away. Thus if you perform an ingame action, you will get visual feedback in ~8.3ms, whereas with 120Hz it will come in 4.1ms.
There is probably some kind of buffering done, so likely your action will not end up in the currently drawn frame but the one after that. So the response will on average come 3/2 frames after your action: 25ms later for 60Hz v.s. 12.5 ms for 120Hz. 10ms faster reaction time should be noticeable.
If the mouse were moving continuously you would be able to see the full trace of its path and not just a few discrete locations along the way. A higher frequency would get closer to this.
Also, in an interactive scenario, the frame rate will impact how quick you get feedback on your actions. With 60Hz, the frames each take 17ms, meaning the next frame will be on average 8.3 ms away. Thus if you perform an ingame action, you will get visual feedback in ~8.3ms, whereas with 120Hz it will come in 4.1ms. There is probably some kind of buffering done, so likely your action will not end up in the currently drawn frame but the one after that. So the response will on average come 3/2 frames after your action: 25ms later for 60Hz v.s. 12.5 ms for 120Hz. 10ms faster reaction time should be noticeable.