Focaccia descends from Latin focus, meaning hearth or fireplace. The Late Latin form focacia (panis) meant hearth bread — flatbread baked directly on hot hearthstones rather than inside an oven. This method of cooking is among the oldest in human civilization, predating enclosed ovens by thousands of years.
The Latin root focus produced an unexpected English relative. In the 17th century, the astronomer Johannes Kepler borrowed the Latin word to describe the point where light rays converge, imagining it as a point of concentrated heat like a hearth. From this technical usage, focus gradually expanded to mean any central point of attention. Focaccia and focus are therefore etymological siblings, both descended from the same Roman fireplace.
Other offspring of Latin focus include the French words feu (fire) and foyer (originally a hearth room, now an entrance hall), the English word fuel (through Old French), and the Provencal bread fougasse, which is essentially southern France's version of focaccia.
In Liguria, focaccia di Recco is a thin, cheese-filled variety considered the regional specialty. Genoese focaccia, thicker and dimpled with olive oil, is the version most familiar outside Italy. Puglia has its own tradition, focaccia barese, topped with tomatoes and olives. Each region treats the basic concept — flat, oil-rich bread — as a canvas for local ingredients.
English borrowed the word in the late 19th century, though focaccia remained little known to most English speakers until the Italian food boom of the 1990s. The pronunciation still trips up English speakers who encounter the double c before i — Italian pronounces it as a ch sound, giving fo-KAH-cha rather than the common mispronunciation fo-KAH-see-ah.