Ultralight balloons (UB) are practically the same as "normal" balloons, but in a smaller edition. The same physical laws and principles apply to them - they fly where the wind blows at the height to which they ascend or descend (according to the principles of Archimedes, rather than Bernaulli). The same rules for flying also apply to them. However, the volume of UB carrier gas is limited by law, which also limits its load, which is practically limited to a maximum of two crew members. Therefore, with ultralight balloons you will not find wicker baskets for several people, but usually only simple, light tubular "benches" for one or two people, on which (in the case of a hot air balloon) bottles with fuel or bags with weights are attached from the outside (in the case of gas balloons ).
Ultralight balloons cannot be used commercially, as is the case with "large" balloons or airplanes. Like other sports flying devices, ultralight balloons are used for air navigation for the pleasure, joy and sporting enjoyment of their pilots/operators at an acceptable cost, with a maximum of one additional person on board, or for training to obtain the qualification of Pilot of an ultralight balloon.
Like any specialty, ultralight balloons also have their inspectors.