1) In a computer display, to refresh is to redraw the image information from memory . Computer or television displays have to be refreshed because they don't have the capacity to hold a stable image. Electron guns in the cathode ray tube ( CRT ) constantly sweep across the screen, redrawing the display. The RAMDAC (random access memory digital-to-analog converter) in the graphics card determines a refresh rate : how many times per second the information will be drawn and the image repainted. At adequate refresh rate levels, a display appears stable, but if a refresh rate is too low a display will flicker and can cause eye strain and headaches.
2) With a Web browser , to refresh (or reload) is to download browser content (such as a Web page or other file) that is already displayed. Refreshing browser content ensures that the most currently updated information will be displayed.