Horizonal frequency, (like 15 for PAl and 30 for VGA) is measured in kHz

Vertical frequency (like 60 for a flickery picture and 100 for a non flickery picture) is measured in Hz.

These pages explain it in some detail:
http://en.wikipedia.org/wiki/Refresh_rate
http://en.wikipedia.org/wiki/Horizontal_scan_rate

Although you might want to read other pages as well for more information, due to the strange use of the word 'shuzam' in the Refresh Rate article.

And to verify that horizontal refresh rate is measured in kHz, my monitor's OSD states the horizonal rates it can do in kHz and the vertical rates it can do in Hz.
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Aha! I get it. You learn something new every day. You know, it never even occurred to me, but thinking about it properly it does make sense. Is it in any way related to the v-sync and H-sync nobs that you sometimes see on old screens - or is that something different again?
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