Why a biscuit is not a biscuit

In British usage, a biscuit is a hard, sweet, low-moisture bake, and a cookie is a specific softer American style. In American usage, a cookie covers the whole family, and a biscuit is a soft, savoury, chemically leavened quick bread much closer to a British scone.

Both uses descend from the same word, whose older sense referred to a twice-baked hard bread made to keep — which is closer to the British meaning, though neither modern usage is the original.

It is the clearest case on this site of a terminology split that produces real failures. A British reader following an American recipe for biscuits is expecting something entirely different from what they will get, and the two products share almost no technique.

The same applies to plain and all-purpose flour, to bicarbonate of soda and baking soda, and to caster and superfine sugar — though those are the same thing under two names, which is a far easier problem.

BakeHQ models aliases with their register attached rather than picking one term as canonical, because both readers are searching for something real and neither is using the word incorrectly.