What is the correct description for hair layering in my case? Professionals only please?

I have hair that is in actuality to the middle of my back in length but you cannot tell because it is extremely curly (spiral) and that is natural. Plus I live in Texas where there is high humidity. So my hair only looks to be at shoulder length.

I have bangs on top that I blow dry straight but the rest of it is one length. I am tired of this much body and someone suggested layering. I am not sure if this is the correct term because layering may actually make my hair MORE full and this is not at all what I want. I want my length to show. Do I ask for "thinning out" or is there another term?

Professionals only please?

What is the correct description for hair layering in my case? Professionals only please?

I know how you feel my hair is very curly and it is very thick it's only a little past my shoulders and I have to use two boddles of hair dye when I dye it and I hate it.....

but my mom used to cut hair and work with it and so I asked her this "in the summer how can I keep my hair straight?" and she said "that is simple just get some sort of gel or something like that," (I use Sheer Blondie stuff that helps alot) and I said "then what do I do?" and she said "put it in you're hair and then straighten it."

that's all the help I can give and I hope that it works!