There are many options in layout programs, and I'm not clear on which options are part of the font file and which are things the layout program does for me.
For example, I'm fairly sure that both bold and italics are additional fonts that are part of a font family, because when downloading fonts, I've seen separate files for italics and bold. I've also read that if a font family lacks an italics variant, many programs will "fudge" it by slanting all the characters.
There are many other things about typography that I don't know who (the font or the layout software) is deciding. Here are a few examples:
- letter spacing
- word spacing
- kerned pairs
- small caps
- lining and old style figures
- tabular and proportional figures
There are probably more that I don't know to ask about.
So what what typographic properties are determined by a font choice and what are strictly determined by the layout program?