Distinguishing between a Boeing 757 and a 767 is easiest if you look at the fuselage width and the nose shape. The 757 is a "narrow-body" (single aisle), giving it a long, skinny "flying pencil" appearance. Its nose is very pointy and sleek. In contrast, the 767 is a "wide-body" (two aisles), making it look significantly fatter and more "bulbous" in the front. Another key "tell" is the landing gear: the 757 sits unusually high off the ground on skinny legs (sometimes called a "moose"), whereas the 767 sits lower. If you look at the main landing gear (under the wings), the 757's bogeys are level, while the 767's bogeys are often "tilted" (rear wheels lower than the front) when the aircraft is in the air. Finally, check the tail cone where the APU (exhaust) is located; the 757 has a rounded tail cone, while the 767 is more stubby. At the gate, the 757 will have 3-3 seating in economy, while the 767 typically has 2-3-2 seating, making the 767 a favorite for passengers who dislike middle seats.