Alternatively called the frame rate, horizontal scan rate, vertical frequency, or frequency. Refresh rate is a CRT (cathode ray tube) monitor measurement in Hz that indicates how often per second a monitor screen image is renewed. For example, a monitor with a refresh rate to 75 Hz means the screen is going to redraw 75 times per second.
Refresh rates below 75 Hz can produce an often imperceptible flicker that may cause eye strain after long viewing. However, having a refresh rate that is too high can lower you FPS (frames per second). Finally, an LCD (liquid-crystal display) does not have a refresh rate; however, if you need to set a rate, values of 40 Hz or 60 Hz can be used.