The wrap is defined by a structural inversion: the bread is on the outside and fully around, not on two opposing faces. A soft flour tortilla or a sheet of lavash is laid flat, loaded across the center, and rolled into a sealed cylinder, so a single flexible flatbread does the containing that two rigid slices cannot. That is the whole engineering. A closed roll holds a wet, loose, mixed filling in one hand without it sliding out the open sides, and it shifts the bread-to-filling ratio sharply toward the filling, because a thin wrapper occupies far less of the bite than two slices of a loaf would.
The craft is in the fold and the moisture, not the recipe. A wrap is a seam under tension, so the filling has to be arranged in a band and kept dry enough at the edges that the roll does not blow out or go soggy from the inside; a creamy dressing is set against drier components rather than pooled at the bottom. The flatbread itself is chosen for pliability above all, soft enough to roll tight without cracking along the fold, and it is often warmed briefly so it bends rather than splits. Once rolled it is usually cut on a sharp diagonal, which is not only presentation: the angled cut exposes the layered cross-section and gives a stable flat end to start eating from without the cylinder unrolling. The filling is built to be balanced in every bite the length of the roll, because unlike a stacked sandwich there is no way to bite through all the layers at once if they are not distributed along it.
The variations are nearly unlimited, because the wrap is a method rather than a fixed filling. A bound chicken or tuna salad, a cold-cut and cheese build, a grilled vegetable version, or a chicken Caesar each runs the same roll-and-seal logic with a different center. The form shades into the burrito and the shawarma wrap, which add their own structural rules, a foil sleeve and rice, or spit-roasted meat and a sauce that is part of the build. Those neighboring traditions deserve their own articles rather than being crowded in here.