An airship is a self-propelled, lighter-than-air aircraft that floats like a balloon but has engines and rudders for steering, using lifting gases like helium (or historically, flammable hydrogen) within a large envelope, with types including nonrigid (blimps), semi-rigid, and rigid (Zeppelins). It can also refer to Airship (the company), a customer engagement platform using AI for personalized messaging across apps, web, and SMS, or even a multiplayer game. The term "Airship" also describes modern projects for autonomous flying ships for efficient, eco-friendly transport.