Viennoiserie
Viennoiserie is the category of baking that sits between bread and pastry: yeasted dough enriched with butter, eggs, sugar and milk. It covers croissants, brioche, pain au chocolat, chaussons and raisin swirls.
The name points to Vienna: the tradition is held to have reached France with Austrian bakers in the nineteenth century, and the word — "things from Vienna" — followed.
Technically it splits in two. Laminated items — croissants and everything derived from croissant dough — are built on layers of butter. Non-laminated ones, brioche above all, get their structure from butter worked directly into the dough.
Both share the same difficulty: enriched dough ferments more slowly than lean dough, because fat and sugar hold the yeast back, and a high butter content demands precise temperature control at every stage.