V-Sync
Also called vertical sync
V-Sync makes a game or app wait for the monitor to finish a refresh before it shows the next frame. It removes tearing but adds input delay and can cause stutter when frames arrive late.
In practice
V-Sync was the standard fix for tearing for many years and still works on any monitor. Its drawbacks are extra input delay and stutter when the frame rate drops below the refresh rate, since frames have to wait for the next refresh. On monitors with variable refresh, that is usually the better choice.
How to check
V-Sync is set per game or in the graphics driver. If a game tears, turn it on and see whether the tearing stops. If it makes aiming feel sluggish, try variable refresh or a frame rate cap instead. The refresh rate test shows the refresh rate the frames are being synchronized to.