Gas balloon

A gas balloon is a balloon that flies in the air because it is filled with a gas less dense than air or lighter than air (such as helium or hydrogen). It is tied to a thread to prevent it from flying up in the air. A gas balloon may also be called a Charlière for its inventor, the Frenchman Jacques Charles. Today, familiar gas balloons include large blimps and small rubber party balloons. Blimps have displaced zeppelins (which are not balloons) as the dominant form of airship.