Gyros (Γύρος) is Greece's defining street sandwich: seasoned meat stacked on a vertical spit, roasted as it slowly turns, shaved off in thin crisped strips and folded into a warm pita with tomato, onion, tzatziki, and a fistful of fries. The name describes the cooking, the turning of the cone against a heat source, and everything good about the sandwich follows from that mechanism. The meat that touches the flame chars and renders; the cook shaves only that outer layer; the next layer is exposed and cooks in turn. Done well, it is a sandwich of contrasts: hot crisp meat against cool sauce, soft bread against the snap of raw onion, all of it eaten standing up.
The build runs in a strict order and each step has a way to go wrong. The meat, most often pork in Greece and very commonly chicken, is marinated and packed onto the spit in overlapping layers so it roasts evenly rather than drying at the edges. As it turns, the cook shaves it in long thin slices; thin matters, because thick slabs stay pale and chewy instead of crisping. The pita is the next decision and a Greek one: it is brushed with oil or fat and flashed on the griddle, sometimes against the spit drippings, until it is soft and pliable with a few blistered spots, not the dry pocket bread of other traditions. Then it is built fast while the meat is hot: meat first, then tomato, raw onion, tzatziki, and fries laid inside the wrap so they steam slightly and absorb juice. The classic failure modes are obvious once you know them: lukewarm meat that has sat off the spit, a stiff cold pita that cracks when rolled, watery tzatziki that soaks the bread to mush, and skimped fries that leave the wrap loose and underfilled. A good gyros is wrapped tight in paper, holds its shape to the last bite, and tastes of charred fat, garlic, and bright tomato in roughly equal measure.
From this template the sandwich shifts by region and protein. Lamb gyros, richer and less common in Greece on cost grounds, is distinct enough to deserve its own article rather than being crowded in here, as is the Athenian reading where the word gyros itself carries a specific local meaning against souvlaki. The mixed-meat cone, the Thessaloniki style with its own bread and proportions, and the plated merida served without bread are each their own preparation and treated separately. What stays constant everywhere is the logic of the turning spit: shave the cooked edge, keep the bread warm and soft, build it hot, and let the tzatziki and tomato do the cutting against the fat.