The refresh rate of a LED screen is the number of times in a second that the LED screen hardware draws the data. This is distinct from the measure of frame rate in that the refresh rate for LED screens includes the repeated drawing of identical frames, while frame rate measures how often a video source can feed an entire frame of new data to a display.
 

On LED screens, increasing the refresh rate decreases flickering, thereby reducing eye strain. However, if a refresh rate is specified that is beyond what is recommended for the LED screen, damage to the display can occur. 
Normally our LED screens  have a refresh rate of over 300Hz, which is more than 5 times the refresh rate of a normal cathode television which is 50Hz (PAL and SECAM) or 60Hz (NTSC). For football stadiums (stadium LED screens and perimeter LED screens) our LED screens can reach a refresh rate of over 800Hz, which means that they won´t show any flickering when recorded with a video camera and broadcasted live on television