The Suite is a French form - a collective term for a set (hence "suite") of dances. It would be hard to actually physically dance to these Orchestral Suites, for in fact they are more like abstract musical essays on dance form; perhaps a Baroque equivalent of "symphonic dances". When you listen to them, dance not with your feet, but with your mind.
It remains titillatingly unclear why or for whom Bach wrote these Suites for. In Baroque Germany, composers called the form Ouvertüren, a reference to the opening movement. When Jean-Baptiste Lully extracted the overture and selected dance movements from his operas, he created the first Orchestral Suites. And indeed, this "collect and play the best orchestral bits" idea continues today.