What are the differences between the three types of becoming? When reading through the Maha Nidana sutta I came across the three types of becoming: Sensual becoming, form becoming, and formless becoming. I am trying to understand what the different forms of becoming are. This sutta does not explain how they are different, it only says that birth occurs if any type of becoming occurs. To try to understand the differences I read the Bhava sutta; this sutta says

&quot;Ananda, if there were no kamma ripening in the sensuality-property, would sensuality-becoming be discerned?&quot;
&quot;No, lord.&quot;
&quot;Thus kamma is the field, consciousness the seed, and craving the moisture. The consciousness of living beings hindered by ignorance &amp; fettered by craving is established in/tuned to a lower property. Thus there is the production of renewed becoming in the future.

This is repeated replacing &quot;sensuality-property&quot; and &quot;sensuality-becoming&quot; with &quot;form-property&quot; and &quot;form-becoming&quot;, and likewise for formless property/becoming.
Ven Thanissaro Bhikkhu mentions in his notes on the Bhava sutta that the Buddha never defines becoming, the Buddha just splits becoming into these three types. From these suttas it appears that knowing what sensuality-property, form-property, and formless-property mean is all there is to knowing the differences in the types of becoming but I haven't been able to find information on what they are.
I think the passage you're asking about (in the Access to Insight translation of DN 15) is this:


  "'From becoming as a requisite condition comes birth.' Thus it has been said. And this is the way to understand how from becoming as a requisite condition comes birth. If there were no becoming at all, in any way, of anything anywhere — i.e., sensual becoming, form becoming, or formless becoming — in the utter absence of becoming, from the cessation of becoming, would birth be discerned?"


I think that's a summary of the previous paragraph, i.e.:


  If there were no birth at all, in any way, of anything anywhere — i.e., of devas in the state of devas, of celestials in the state of celestials, of spirits in the state of spirits, of demons in the state of demons, of human beings in the human state, of quadrupeds in the state of quadrupeds, of birds in the state of birds, of snakes in the state of snakes, or of any being in its own state — in the utter absence of birth, from the cessation of birth, would aging and death be discerned?


I.e. the types of becoming correspond to birth in the various planes of existence.

Dharmafarer's introduction to the Bhava Sutta describes them as follows:


  Another interesting feature of the two discourses is their treatment of the
  three realms as “low” (hīna dhātu), “middling” (majjhima dhātu), and “subtle” (paṇīta dhātu), that is,
  the sense-world, the form world, and the formless world, respectively.
  
  The “lowly” sense-realm (kāma,dhātu) [§1b] is the realm of beings dependent on some form of physical
  senses, and is the lowest of the three existential spheres. It comprises the human world, the subhuman
  realms (the hells, the animal kingdom, and the ghost realm of the departed), and the six lower heavens.6
  It
  is said to be “low” (hīna) because the beings there are dependent on the physical senses and the mind.
  
  The “middling” form realm (rūpa,dhātu) [§2] is the realm of blissful dhyanic existence of radiant
  fine-materiality,7 whose beings still have the faculties of seeing and hearing, but which along with the
  other physical senses are temporarily suspended in the four dhyanas.8 The beings of such realms are called
  brahmas (brahmā), or “high gods,” who normally have almost nothing to do with the sense world,
  since they are absorbed in their celestial dhyanic bliss. When they do appear in the sense-world, they
  apparently have to emerge from their dhyanic state.9
  
  The “subtle” formless realm (arūpa,dhātu) [§3] comprises of beings of pure energy, that is, without
  any physical form whatsoever.10 They exist only as varying refined states of the four mental aggregates
  (feeling, perception, formations and consciousness). These beings have no contact with the sense-world
  whatsoever.11