The hot air balloon is an airship.
It flies when the air inside the envelope gets hot and it creates a thermal differential with the outside temperature. What is the fact that makes the thermal differential raise the hot air balloon? The hot air has more pressure and it tends to occupy more volume. But the envelope retains the hot air, and this hot air has less density than the cold air outside, what creates a less weighing air inside the envelope comparing to the air outside. This differential of air weight makes the hot air balloon rise.
Depending on the height of the hot air balloon, there are different wind streams that will guide the balloon. For this reason, a balloon flight will always be unique.
The three most important parts of a balloon are the envelope, the burner and the basket.
The envelope contents the hot air that makes raise the balloon.
The burner is the one that heats the air in the envelope, doing the famous sound of a balloon flight.
The basket is the part of the balloon where the passengers and the pilot goes.
Camins de Vent has an accessible basket for passengers with reduced mobility, with a door and a seat.