A hot air balloon consists of an envelope that contains hot air to remain airborne, with a gondola suspended below for passengers. It works by heating the air in the envelope to rise and remains aloft as long as the air inside stays warmer than the outside air. The hot air balloon was the first successful human-carrying flight technology.

2. What is a Hot Air Balloon?
The hot air balloon is the oldest human-carrying
flight technology
It consist of a bag called envelope that helps
maintain the hot air. Beneath where passengers
ride is called gondola.
First air transportation device

3. How does it work?