By heating the air inside the balloon with the burner, it becomes lighter than the cooler air on the outside, causing the balloon to float upwards. To land, the air inside is allowed to cool meaning the balloon slowly begins to descend. An altimeter (to measure altitude), a rate-of-climb meter, and an envelope temperature gauge are the only instruments used in the balloon. Amazingly, the pilot can control the altitude of the balloon within a matter of a few feet !
If the pilot wants to move in a particular direction they simply ascend and descend to the appropriate level and ride with the wind. This is however limited to the variation in wind direction on the flight day.