What it means
"First class" denotes the top service tier of a commercial passenger transport product. In contemporary use the phrase refers predominantly to commercial aviation, where it identifies a cabin above business class with larger seats (often in suites or semi-enclosed cabins), dedicated cabin crew, full-flat or apartment-style sleeping, named meal service designed and credited to specific chefs, a separate ground product including chauffeur transfers and dedicated lounges, and prices that begin at several multiples of business-class fares on the same routes.
Origin and trade adoption
The phrase originates in 19th-century British railway classification. From the 1830s opening of the Liverpool and Manchester Railway onwards, British railway companies classified passenger carriages into three tiers - 1st, 2nd, 3rd - with 1st class denoting closed compartments, upholstered seating, and a price premium. The convention spread across European and American railways through the second half of the 19th century and entered ocean travel in the same period: by the 1880s the major North Atlantic operators (Cunard, White Star, Hamburg-Amerika, Norddeutscher Lloyd, the French Line) all classified accommodation as First, Second, and Third. First Class on a North Atlantic liner meant the upper decks, the named dining rooms, the larger cabins, and access to the saloons.
The migration into commercial aviation came after the Second World War. Pan Am's "President Special" service (1955) is among the earliest branded First Class products in international aviation; Pan Am's First Class through the 1960s to the 1990s set the standing American template. The British state carriers - BOAC and later British Airways - developed comparable First Class on the trans-Atlantic and Empire routes through the same period.
What to expect
From the 1990s onwards, First Class has retreated from many carrier networks in favour of upgraded business class. The decisive shift was the introduction of fully-flat business seats - British Airways' Club World in 2000 is an early benchmark, with Singapore Airlines and Cathay Pacific following - which narrowed the experiential gap between Business and First. Several North American carriers reclassified long-haul "First Class" as "Business First" or eliminated the tier entirely. By the mid-2020s, genuine First Class - distinct from Business in cabin, seat, service, and ground product - is maintained on a relatively small set of carriers: Emirates, Singapore Airlines, ANA, Japan Airlines, Lufthansa on limited routes, Air France's La Première, British Airways on limited routes, and Etihad. Several have introduced suite or residence products (Emirates Suites, Etihad's The Residence, Singapore Suites) that sit above conventional First and effectively constitute a new tier.