Gary''s Student wrote <<Width is measured in points (12 points to the
inch)>>
I don't think this is correct. The width of, for instance, the letters 'I',
'M', 'N and 'W' are very different. I believe there is a convention placing
letters in four groups according to width. In any case width is
proportional to the height so will vary accordingly.
All that said, the height and width of characters on the screen may be
varied according to the zoom factor but the zoom factor doesn't in itself
change the size of characters on a printed page. The standard printers'
measurement is 'points' is an actual and physical measurement. However, I
wouldn't trust that any stated font size isn't changed by either word
processing or printer driver software. In the days of manual print setting
it was necessary to know exactly what you're getting but nowadays print size
can be best regarded as a relative guide.
Regards.
Bill Ridgeway