But because I like to explain things simply (sometimes too simply, lol) I'll give you a general idea.
Bardon's theory on elements (and Hermetics in general) is of the theory that everything corresponds to an element- everything has an elemental characteristic that describes it and could be said to metaphysically be contained in it. So when you study the elements in detail, you can theoretically reduce any condition to it's elemental attribute, and instead of attacking a problem as a problem directly, you can deal with the element that it corresponds to and the problem will become undone.
This is not unlike the theory that everything that exists in the physical can be described as an idea in the mind of God, and this idea manifests symbolically. If you can figure out the symbol, you can find out what the situation symbolizes and go with that approach, instead of putting the attention on the situation or problem.
Same idea, sort of.
I can go on and on about this, but I think you get the idea.