In a question we use "que" if we want to know the meaning of an object or what the object is, in general like : " que es el tango? Es un baile tipico argentino" , as you can see the answer gives an explanation of what "tango" is.

Then we use " cual" when we want to know the name of something, it's more specific like " cual es el baile tipico argentino? El tango" .