Blimps, also known as airships or dirigibles, are large, lighter-than-air vehicles that are filled with gas, typically helium or hydrogen. They have a rigid or semi-rigid structure and are used for various purposes, including advertising, surveillance, and tourism. Blimps are steered using propellers and can travel at relatively low speeds compared to airplanes. The design of a blimp includes a long, elongated envelope that holds the gas, and a gondola where passengers and equipment are located. Unlike hot air balloons, blimps can be controlled in the air, allowing for more precise navigation. They are often seen at sporting events and festivals, providing aerial views and promotional opportunities.