from
The Free On-line Dictionary of Computing (8 July 2008)
horizontal scan rate
<hardware> (HSR) The measure of how many {scan lines} of
{pixels} a {monitor} can display in one second, expressed in
kHz (generally somewhere between 20 and 100 kHz).
The HSR is controlled by the horizontal sync signal generated
by the {video controller}, but is limited by the speed with
which the monitor can scan the electron beam horizontally
across the screen and then return it to the beginning of the
next line.
(1996-02-09)