Type designers usually do not create new characters, i.e. the meanings of those pictures, or, more technically put, ‘the smallest component of written language that has semantic value.’ We don’t invent alphabets, we merely re-interpret existing ones.

Type designers create new glyphs, i.e. pictures representing characters.

Characters versus glyphs

A glyph can also represent more than one character at once. Take an f_f_f ligature as an example. It represents three f characters in a row. Ligatures do not have Unicodes, because the separate characters already have codes and the the fact that it’s a ligature does not change the meaning of its parts.

What if you want to share the same glyph shape between two Unicode values? There are a few situation where you would need that. E.g., the symbol increment U+2206 and the Greek letter Delta U+0394 should look the same. There is a similar issue with Ohm U+2126 and Omega U+03A9. Or, you are creating an all-caps font. Or you simply want to reuse the same space glyph for both the space U+0020 and non-breaking space U+00A0.

And get a list of characters in a font like this:

Characters are logical text units identified by Unicode codepoints, whereas glyphs are graphical font units. The distinction between character and glyph is critical to understanding FontLab, and fonts in general.

A Glyphset is the glyph repertoire of a font, i.e. all glyphs present in the font. The old term for this repertoire was “character set”, but it is misleading because in modern font technology, a font is a collection of glyphs, not a collection of characters.