Wikipedia
Flicker-free is a term given to video displays, primarily cathode ray tubes, operating at a high refresh rate to reduce or eliminate the perception of screen flicker. For televisions, this involves operating at a 100 Hz or 120 Hz hertz field rate to eliminate flicker, compared to standard televisions that operate at 50 Hz ( PAL, SÉCAM systems) or 60 Hz ( NTSC), most simply done by displaying each field twice, rather than once. For computer displays, this is usually a refresh rate of 70–90 Hz, sometimes 100 Hz or higher. This should not be confused with motion interpolation, though they may be combined – see implementation, below.
Televisions operating at these frequencies are often labelled as being 100 or 120 Hz without using the words flicker-free in the description.