what does the 60 mean in the resolution 1920x1080x60?

shadybk

Distinguished
Dec 23, 2015
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I just built a gaming pc and I have a 1920x1080 60hz benq monitor and I started playing diablo 3 today when I noticed the screen resolutions options had a third component to them. There were options like 1920x1080x60 1920x1080x59 1920x1080x58 1920x1080x30 and many more, what does that third number mean?