Cosmogony is a bit more metaphysical than cosmology, which is more of a mainstream science.
Cosmogony can be distinguished from cosmology, which studies the universe at large and throughout its existence, and which technically does not inquire directly into the source of its origins. There is some ambiguity between the two terms; for example, the cosmological argument from theology regarding the existence of God is technically an appeal to cosmogonical rather than cosmological ideas. In practice, there is a scientific distinction between cosmological and cosmogonical ideas.
Physical cosmology is the science that attempts to explain all observations relevant to the development and characteristics of the universe as a whole. Questions regarding why the universe behaves in such a way have been described by physicists and cosmologists as being extra-scientific, though speculations are made from a variety of perspectives that include extrapolation of scientific theories to untested regimes and philosophical or religious ideas.
Attempts to create a naturalistic cosmogony are subject to two separate limitations. One is based in the philosophy of science and the epistemological constraints of science itself, especially with regards to whether scientific inquiry can ask questions of "why" the universe exists. Another more pragmatic problem is that there is no physical model that can explain the earliest moments of the universe's existence (Planck time) because of a lack of a consistent theory of quantum gravity.
