Realm of Form
The environment of the gods who possess form. Form aggregate, Form that is a phenomena source, and Visual form. Visual Form: The object of eye awareness. Fourth of the twelve Dependent Originations; a body comes into being to carry our karmic inheritance, represented by a boat carrying men. Form that appears exclusively to mental awareness, such as a dream mountain that appears to a dream eye awareness. Rūpadhātu;
The Rupadhatu (Pali: Rupaloka; Tib: gzugs.kyi khams) or "Form realm" is, as the name implies, the first of the physical realms; its inhabitants all have a location and bodies of a sort, though those bodies are composed of a subtle substance which is of itself invisible to the inhabitants of the Kamadhatu. According to the Janavasabha Sutta, when a brahma (a being from the Brahma world of the Rupadhatu) wishes to visit a deva of the Trayastrimsa heaven (in the Kamadhatu), he has to assume a "grosser form" in order to be visible to them.
The beings of the Form realm are not subject to the extremes of pleasure and pain, or governed by desires for things pleasing to the senses, as the beings of the Kamadhatu are. The bodies of Form realm beings do not have sexual distinctions.
Like the beings of the Arupyadhatu, the dwellers in the Rupadhatu have minds corresponding to the dhyanas (Pali: jhanas). In their case it is the four lower dhyanas or rupadhyanas. However, although the beings of the Rupadhatu can be divided into four broad grades corresponding to these four dhyanas, each of them is subdivided into further grades, three for each of the four dhyanas and five for the Suddhavasa devas, for a total of seventeen grades (the Theravada tradition counts one less grade in the highest dhyana for a total of sixteen).
The devas of the Rupadhatu have physical forms, but are sexless and passionless. They live in a large number of "heavens" or deva worlds that rise, layer on layer, above the earth. These can be divided into five main groups:
Each of these groups of deva worlds contains different grades of devas, but all of those within a single group are able to interact and communicate with each other. On the other hand, the lower groups have no direct knowledge of even the existence of the higher types of deva at all. For this reason, some of the Brahmas have become proud, imagining themselves as the creators of their own worlds and of all the worlds below them (because they came into existence before those worlds began to exist).
Physically, the Rupadhatu consists of a series of planes stacked on top of each other, each one in a series of steps half the size of the previous one as one descends. In part, this reflects the fact that the devas are also thought of as physically larger on the higher planes. The highest planes are also broader in extent than the ones lower down, as discussed in the section on Sahasra cosmology. The height of these planes is expressed in yojanas, a measurement of very uncertain length, but sometimes taken to be about 4,000 times the height of a man, and so approximately 4.54 miles (7.31 km) or 7.32 kilometers.\
See; Three Realms.
Second ground: The Joyful Stage of Leaving Production is the first dhyana, a level of deep awareness, contemplative calm, and one-pointed concentration.
The four dhyanas are meditative techniques which produce a state of mental emptiness (samadhi). This is the first formal level on the path to enlightenment and is marked by happiness, joy, clear reasoning, and the state of investigation and examination.
Third ground: The Joyful Stage of the Arising of Samadhi is the second dhyana of joy and pleasure, but now free of investigation and examination. At this stage sexual desire has ceased.
Fourth ground : The Stage of Wonderful Bliss of Being Apart from Joy is the third dhyana of happiness and equanimity, but now without joy.
Fifth ground: The Stage of Renouncing Thought is the fourth dhyana which is the purity of equanimity without pain or pleasure.