Like many specialized professionals, automotive designers have a language all their own, and it varies by country and carmaker and evolves over time. Volkswagen is proud of the styling of its Arteon sedan (justifiably so, if we may insert an editorial view) and took this opportunity to put together a glossary of design terms with the Arteon as the model. Many of the terms will be familiar, while some of the terms may be new—and there may be a few you take issue with. In any event, it’s an interesting read. We’re sharing it here verbatim.

A-Line: If you traced a vehicle’s silhouette from front to rear, you’d have the A-line, or main profile. This line often defines the entire character of a car, and a few millimeters here and there can mean the difference between sleek or dull.

Beltline: The horizontal line that divides the sheetmetal from the glass in a vehicle. Just as a higher or lower beltline on a human body drastically alters a person’s look, the height of a vehicle’s beltline can make it look sporty and menacing or welcoming and airy. In the Arteon, the beltline is balanced for a classical feel.

Character Line: The creases running horizontally along the side of the vehicle that give it a visual definition. “We have a line,” says Klaus Bischoff, Volkswagen Head of Design, “that runs through the entire car and brings the volume of the Arteon even closer to the ground. This line starts in the radiator grille at the front and runs cleanly over the side profile and into the tail lights.” At the rear, it develops into a sharp undercut, which visually reduces the height of the Arteon and carries the strong shoulder section upwards.

C-Pillar: Car designers have a lettering system for the pillars that contain the passenger compartment when viewed from the side; the A-pillar frames the front, the B-pillar is where the door edges meet, and the C-pillar frames the rear side windows. Over time the C-pillars and the angle formed where the sheetmetal and glass meet have become brand touchstones for several automakers and key models — few more so than the Volkswagen Golf. In the Arteon, the C-pillar follows the long arch of the rear hatch, ending in a discreet angle with a premium touch of glass and chrome.

Down the Road Graphics: If you’ve ever tried to identify a car at night simply from the shape of its headlights, you’ve memorized what designers call “down the road graphics.” With the arrival of LED daytime running lights, there are more ways than ever to distinguish vehicles through light. The Arteon makes the most of this with its dramatic light signature of the daytime running light that angles into the grille, framing the LED headlights.

Fastback: The car body term dates back to before World War II, when automakers first began optimizing aerodynamics. Long roofs that slope down to a car’s trunk provide several aerodynamic benefits, and eventually such profiles were called fastbacks. The fastback shape of the Arteon gives it a dynamic and elegant look among midsize sedans.

Flitzer: The German term for the side badge on Volkswagens where the front door line meets the fender.

Greenhouse / Day Light Opening (DLO): The shape and total area of the glass around a passenger compartment in a vehicle. Owners generally favor open, airy greenhouses, but too much glass can make for awkward exterior design. Sports cars often have the smallest DLOs that emphasize performance at the expense of visibility. The best designs offer a balance between extremes, while panoramic sunroofs such as the one in the Arteon, add a further dimension.

Joint Line: Any place on a vehicle where two body panels meet. Joint lines are rarely the centerpiece of a vehicle’s design, but they can add or detract greatly from the overall impression. The joint line where the hood of the Arteon meets the front wheelarch shows how graceful such seams can be.

Overhang: As seen from the side, the part of the car that extends ahead and behind of the wheelarches. Classic American cars commonly had a foot or two of sheetmetal and frame sticking out in front and back. In the modern era, smaller overhangs have become the more preferred style (and provide more assured handling, as more of the vehicle’s weight lies within the wheelbase.)