(1) The number of times per second all the pixels in a display screen are re-energized. LCD and OLED screens have a maximum refresh rate of 60 to 240 Hz. In the past, CRTs required constant refreshing to keep the phosphors activated even when there was no change in the image. See
pixel response time and
vertical scan frequency.
(2) The number of times per second that a DRAM chip is re-energized. See
dynamic RAM.