What is the true meaning of Kaya Sankhara, Vaci Sankhara and Citta Sankhara I am trying to find a right description of the word Sankhara in dependent origination which includes Kaya Sankhara, Vaci Sankhara and Citta Sankhara.
I have not been able to understand what they mean. Would you please help me understand what each of them mean. 

When it is said volitional activities from what I have read I think that means something that is done by intention and free will in the present moment (even if we are not aware that we are doing it with intention and free will) Now I have heard that they are kamma in what sense do they mean that they are kamma? I have also heard that they are product of our past actions so that contradicts the notion that they are actions one does with free will (volitional) beacuse they are a result of our past not an intentional action in the present done with free will. Where does Kaya Sankhara or breathing in and out come with all of this? How can that be intentional action in the present or as in the other theory the result of past kamma. Is vaci Sankhara and Citta Sankhara product of our past kamma or is it something that we we are doing with free will and volition in the present moment that can be stopped beacuse it is all free will? Does the past decide our present Sankharas or is it all done by free will and intention in the present and that would mean that it is in our control.

You see I have many questions and I hope someone can clarify that for me. But the most important is to clearly understand what do Kaya Sankhara, Vaci Sankhara and Citta Sankhara really mean I have seen many different views and I am confused and therefor I would really want to know it to progress in my spiritual path.
Sankara is conditioning which puts together or makes or forms something.


Kaya Sankhara - this what sustains keeps the body together hence the breath. If breathing stops the body falls apart.
Vaci Sankhara - this is what sustains the formations of verbal throughs. Before speech thoughts need to form, without them one cannot speak. 
Citta Sankhara - this is what causes a mind to arise. Feeling and perceptions are what causes a mind to arise.


How this is relevant in meditation is given here.