There are two basic approaches in controlling the gameloop speed
1. Use a fixed framerate (for example 60 fps)
2. Go "flat out" or with fixed small sleep and calculate all movement based on the deltaTicks between frameloops (fast machines could for example run at 100fps and slow at 40)
1 is what Keldon described. (Using synchronization or more commonly calculate sleep so that each game loop takes the same time)
The game always plays the same
Easy to program
Faster computers will not be utilized fully
Game will not be playable at all/behave differently on computers that not quite can produce the fixed framerate.
2. AAA games will typically use this and many hobby games as well
Utilized the power of the machines very well.
Game might behave slightly different on computers with different performance
A bit more complex to code
What you saw in the 4K code was a clever way to try to get the game to always play the same at the same time as the computer is utilized to the max.
A slight performance hit (if the logic part takes a relevant time compared to the draw task), since logic is executed several times per loop instead of one.
The game loop is still tick based so the logic is still a bit more complex than fixed framerate.
Behavior will not be 100% identical on different computers, just more similar.
I hope it is possible to understand my brief explanation and that I haven't said anything completely wrong