Pentagrams and Hexagrams, invoking and banishing?? Options

I'm not quite sure if I fully grasp this whole pentagram and hexagram thing yet. so I'm going to post what I think is going on and then leave it open for corrections.

There's a banishing and invoking varient of the pentagram and hexagram for each element.
Now in raw assumption a banishing pentagram of fire would remove the presence of any energy of the element of fire? And likewise with other pentagrams? Or is it different than that.

And an invoking pentagram of fire would add the presence of the element's energy?

This is what's really puzzling me, the purposes of these. Aside from LBRP and LBRH which are well explained. But could someone give an example of uses and how one would might go about the use of these other pentagrams and hexagrams?

Thanks

the banishing pentagrams are for banishing a certain element. and with that the effects it has on you, freeing you from the influence of that energy. If you feel sad you could do the banishing ritual of water.
(or the invoking ritual of air)

there are several reasons for doing an invoking ritual.
1. To get the effects of a certain element into your life (see above)
2. To do gray magick, if you need the elements energy in your workings (see below)
3. To attune yourself to the element in the GD elemental grades, Getting to know a certain element and studying it.

It kind of points itself out when doing gray magick:

When creating an elemental, you would do the invoking ritual of the pentagram for a certain element.
Then you would use that elemental energy you just invoked to shape the elemental from.
Then you can give the new being you created a name and purpose, to do certain tasks that corresponds to its element.