A monitor and a game measure time separately. The monitor refreshes at a fixed interval, and the game produces frames whenever it finishes them, which creates a persistent coordination problem.
The display refreshes whether a frame is ready or not
A conventional monitor updates its image at a fixed rate, drawing whatever is in the buffer at that instant. It does not wait for the game.
If a new frame arrives midway through that update, the upper part of the screen shows the old frame and the lower part shows the new one. That visible seam is tearing.
Tearing is most noticeable during horizontal camera movement, because the two halves of the image are offset from each other along the direction of motion.
Waiting for the refresh introduces its own problems
Synchronising the game to the display removes tearing by holding each frame until the next refresh begins. The image is always whole.
The cost is that a frame finishing slightly late waits for an entire refresh interval, so the effective rate drops to a fraction of the display's rate rather than falling gradually.
That produces a sharp, uneven judder as the game alternates between rates, which many players find worse than the tearing the setting removed.
Variable refresh makes the display follow the game
Adaptive refresh technologies invert the relationship, letting the monitor vary its refresh interval to match when frames actually arrive.
This removes tearing without the waiting penalty, because the display adjusts rather than the game. It works within a supported range of rates.
Below that range the display must repeat frames to stay within its limits, which is why very low frame rates still feel unstable on adaptive panels.
Frame pacing matters separately from frame count
An average frame rate says nothing about whether frames arrived evenly. A game producing frames at irregular intervals looks worse than a steadier game with a lower average.
Uneven pacing usually comes from work that occurs occasionally, such as loading assets or compiling shaders, rather than from insufficient rendering power.
This is why capping a frame rate slightly below what the hardware can achieve often looks better. The cap enforces regular intervals the hardware can consistently meet.
Latency is a separate quantity again
The delay between an input and its visible result includes input processing, simulation, rendering, queuing and display response, and each stage adds independently.
Queuing several frames ahead raises throughput while adding delay, which is why competitive players reduce buffered frames at some cost to smoothness.
A player can therefore have a high frame rate and poor responsiveness at once. The two are related but not the same measurement.