ABOUT TICK RATE SIMULATOR
Server tick rate is the frequency at which the server calculates the game's state, and sends that update to all the players so their world view is synchronized.
The tick rate simulator tries to simulate what the server sees at the specified tick rate.
HOW IT WORKS
The red moving target refreshes at 60 times per second (60fps). The green one that ghosts the red target refreshes at the fps according to the specified tick rate (12Hz).
Note: browsers can only render up to 60 fps. Chrome on Android now supports 120hz screens, however the code running here forces 60 fps and the ghost target follows that base fps.
DESYNC
Desync is basically slow tick rate + network latency.