the picture below shows how the hot air balloon

The diagram depicts the structure of a hot ballon and the mechanism behind its operation. Overall, the hot air balloon consists of three main components namely envelope, burner and basket. The way it works could be based on the thermal regulation of hot air. As can be seen from the diagram, the envelop makes up a huge part of the balloon and functions as a place to hold hot air. On the top of it is a parachute valve that acts as self-sealing flap, enabling the pilot to freely control the amount of hot air released into the air. The envelop itself consists of many gores which are strips running across the envelop vertically from the top to the skirt. These gores contains smaller parts known as panels. The burner is located under the skirt, and it is used together with propane cylinder to mix propane with air, producing flame to heat the air inside. The basket is where the propane cylinder is stored and also used to accommodate passengers.