Brand typography
The typefaces a brand uses and the rules governing them: which faces, which weights, and a defined scale of sizes, line heights and spacing for each level of text. Typography is treated as a system rather than a font choice, because consistency comes from repeatable relationships between sizes, not from the faces themselves.
Brand typography is not Font pairing.
A font pairing names two typefaces that sit well together and answers nothing else. Brand typography specifies the scale, weights, line heights, spacing and which level of text uses what, and that is the part which actually determines whether two people produce work that matches.
In practice
Typography is the highest-frequency asset a brand owns. The logo appears once per piece of work, if at all. Type appears in every line of every piece. That frequency is why typographic inconsistency tends to be felt before it is noticed, and why a brand can hold its colours perfectly and still look as though it was assembled by several people who never met.
The argument almost everybody has is about the font pairing, and it is the least useful decision to labour. A pairing answers a single question, which two families to use, and then stops. The questions that come up in practice are different and recurring: how large is a heading relative to body text, what happens at the level below that, how much space sits between a heading and the paragraph under it, which weight is permitted for a caption. A pairing answers none of those, which is why work built from a pairing alone still fails to match.
A type scale answers them in advance. It fixes a base size for body text, a defined set of steps above and below it, a line height for each step, and the weights permitted at each level. Two people working from the same scale produce work that lines up even if they have never spoken. Two people working from the same pairing produce work that shares typefaces and agrees on nothing else. The scale is the part that makes typography reproducible, so it is the part worth writing down first.
A complete specification usually also covers measure, the comfortable line length for body text, letter-spacing adjustments at display sizes, whether all-caps is permitted and where, and how numerals behave in tables. It should name the fallbacks too. A typeface that is not licensed for the web, or not installed where the work is actually made, will be substituted by whoever is in a hurry, and that substitution is drift arriving quietly.
One well-built family with a wide weight range will usually outperform a pairing chosen for contrast, because the range supplies hierarchy without introducing a second personality. Where a second face is genuinely warranted, the honest reason is functional, such as a display face that would be unreadable at paragraph length, rather than a wish to look more designed.