font, ➔ glyph, hot metal, cold type, font family, (schrift)schnitt, unterschnitt, ligatur, ... font handling in Windows... (E:\FM-specials\Tips\Font_issues)
Schrift, schriftsatz [n, masc.]
In traditional typesetting (cold type, hot metal) parlance, "font" actually referred to a single drawer full of characters, which would contain a single size of a single style of a given typeface. In this usage 10pt Times Roman is a different font from 10pt Times Italic or from 12pt Times Roman because each of these was sorted into a separate type drawer.
In the world of electronic type, one usage of "font" refers to the set of character outlines that are scaled up or down to produce a single set of glyphs in any specified size; this is the usage that we find on the OS level, where we have to install each variant version of a typeface as a different font file (e.g. Time, Times Bold, Times Italic, Times Bold Italic).
The other usage in electronic type is found in the user interface of most applications (programs), where "font" is generally used in a way that includes weight and angle variations (bold, italic, etc) as well as a single typeface and style; this usage treats "font" as roughly synonymous with "typeface".
And then some type foundries (producers of fonts) came along and used a common name for a whole series of typefaces that are designed to have a "family resemblance", such as the Univers typefaces.
I'm not sure how this maps onto the group/family/font/series hierarchy that Chris Seal mentions in his (or is it "her", Chris?) posting because it's unclear (to me, at least) what characteristics constitute different series of a particular font.
But even if you subscribe to the most inclusive usage of "font" (the way most applications use the word) it still makes sense to consider each of the numerically-named variations of Univers to be a different font since many of them incorporate shape and proportion differences as well as weight and angle variations.