Follow the moving block with your eyes. A faint trail behind it is ghosting (slow pixel response); a bright halo ahead or behind is overdrive artifacting. The full-screen UFO test below does this at your exact refresh rate with speed control.
Ghosting is slow pixel response: the panel can't finish changing color before the next frame, leaving a smear behind moving objects — worst on VA panels in dark scenes. Overdrive pushes pixels harder to transition faster; too much of it overshoots the target color and paints a bright inverse ghost (coronas) ahead of the object, which looks worse than mild ghosting. Almost every gaming monitor has an overdrive setting (named OD, Response Time, TraceFree, AMA…) with 3–5 levels — the right level is almost never the maximum: run the UFO test and pick the highest level that shows no corona.
Open the monitor's OSD and find the overdrive setting (Response Time / OD / AMA / TraceFree). Step it up while watching the UFO test; stop at the level before a bright halo (inverse ghosting) appears. On adaptive-sync monitors, test at your actual in-game frame rate — overdrive tuning shifts with refresh.
Yes. VA panels smear most in dark transitions ('black smearing'), IPS is quicker but can corona with aggressive overdrive, TN is fastest but looks washed out, and OLED has essentially instant response with no conventional ghosting.
No. MPRT figures involve backlight strobing at maximum settings, not everyday pixel response. GtG response and an actual UFO test tell you what you'll really see.