Refresh rate is the number of frames that refresh themselves per second that display draws an image on the screen, and it is measured in hertz(Hz). Refresh rate is different from frame rate, which defines how many frames the video displays every second. Higher number of hertz means higher refresh rates, thereby resulting in smoother and seamless motion on a screen.

Refresh rate indicates how many times per second a display can renew a screen image.

This picture shows the difference between a 60Hz and 120Hz refresh rate and how the difference affects the image we see on the screen.

The higher the hertz is, the more seamless and smoother screen with less flickering can be displayed like below image.