Fixed updating is a technique for achieving frame rate independence. It limits the amount of updates on fast computers and it makes slower computers update multiple times at once. You have control of how much time you want in between of two frames (which I call the step time) For fixed updating you don't really need a delta time to multiply your change with, since there is (kinda) always the 'same amount' of time in between of two updates, but if you change your step time, the values that aren't multiplied with the step time will update faster/slower too.
try turbo mode, the dot won't move faster
