Rigid Structure: Unlike blimps, which are non-rigid and rely on gas pressure to keep their shape, Zeppelins have a Duralumin frame (metal skeleton) that allows for a larger size, which can span up to meters or more. Origin: Named after Count Ferdinand von Zeppelin, who patented the design in 1895 and launched the first successful airship, LZ1, in 1900. WWI & Commercial Use: During World War I, the German military used them as bombers and for reconnaissance. In the 1920s and 30s, they were used for transatlantic passenger travel, with famous examples including the Graf Zeppelin and the Hindenburg. The Hindenburg Disaster: In 1937, the hydrogen-filled Hindenburg caught fire while landing, which essentially ended the era of large passenger-carrying rigid airships. Modern Day: Modern Zeppelins (like the Zeppelin NT) are smaller, semi-rigid, and use non-flammable helium for tourism, surveillance, and advertising.