In a simple way I can tell you that “citta” is what you experience and “nama-rupa” is what is experienced, even though the codepedence is total during the course of a lifetime. In fact we could talk more about contact.
Nama-rupa is the interface.
Rupa is the part of the interface in charge of providing the basic input / output system, or in other words, the senses. Proprioception is used for Nama to organize the body and the equilibrium to place it in the conceptual space.
With regard to sight, for example, rupa provides flashes of colors of 50ms every 250ms, or four per second. From there, conceptualize by filling in the dark spaces (90% of the time looks black) interpolating, and later by contrasting color, creates shapes. Already with shapes and colors are passed to nama for the process of recognition buying it with stored qualias. The one that most resembles is named with the label. Thus we see a “tree.”
Sound operates the same, from perceived vibrations to hearing “words” …
This is verified experimentally by means of zero-based meditation, from the second hour of being without a single thought.
Nama is the part of the interface that contains “concepts”, or “memes”. Its basic units are a label and a set of qualias. This set is used for the process of identification of qualia contributed by rupa, in order to realize the conceptualization. In Nama live the concepts, being the strongest I.
Citta in an ordinary person only attends to nama-rupa constantly. But Citta can perceive without perception, (neither perception nor non-perception), and when she has access to Wisdom.
The natural mode of citta is the fourth immaterial jhana, and there it really rests.
Death is the end of nama-rupa: the senses and memory are lost. But as long as there is existence, another nama-rupa will appear. Different models of nama-rupa are demons, animals, petas, humans, and all the variety of “luminous beings”.
The different modes of citta that interact with different models of nama-rupa, is what the Buddha called “dwellings” or “seasons”.
The non-return is to eradicate the attachment in the present human nama-rupa.
The total liberation consists in accessing all modes of citta and eradicating all attachment there. Fundamentally in the modes of devas, where attachment is very strong. They are modes of strong attachment and weak ignorance. Hell is the opposite. That is why usually after deva one goes to hell.
The exercises to achieve this consist in climbing up all the jhanas, from the first material to the fourth immaterial and remaining in cessation, and then lowering. Each level corresponds to a mode of operation (dwelling), in which attachment must be eradicated.
Liberation consists in breaking the codependency of nama-rupa with citta, formed from the adherence of citta with nama-rupa, so that when nama-rupa dies, citta is released.
All this you have in the mahanidana sutta and in sutta of the dependent origin. But it requires a finer translation.