Question: a font is a set of characters of a certain design

Answer: Yes, In modern usage, with the advent of digital typography, ``font'' is frequently synonymous with ``typeface''. In particular, the use of ``vector'' or ``outline'' fonts means that different sizes of a typeface can be dynamically generated from one design. Each style may still be in a separate ``font file''--for instance, the typeface ``Bulmer'' may include the fonts ``Bulmer roman'', ``Bulmer italic'', ``Bulmer bold'' and ``Bulmer extended''--but the term ``font'' might be applied either to one of these alone or to the whole typeface.