|The general scheme of the Hermopolis creation myth, wherein the primordial god family of eight gods called the “Ogdoad” engenders the sun god Ra-Atum (Atum-Ra) who in turn engenders the Heliopolis 9-god family called the Ennead.|
In creation myths, Hermopolis creation myth is the creation myth of the Egyptian city of Unet, in Upper Egypt, called "Hermopolis" in Greek, according to which the first thing that came into existence in the universe were eight pairs of gods: 
1. Nun and Naunet | Primeval water2. Huh and Hauhet | Spacial infinity3. Kuk and Kauket | Darkness4. Amen and Amenent (Amaunet) or Niau Niaut [alternative] | Hiddenness
This group of eight gods are called the "Ogdoad", which is Greek for eight.
In 2400BC, the religious power center in Egypt switched from Memphis, and their Ptah-centric creation myth (see: Memphis creation myth), to Hermopolis and one centered on the an 8-god family called the “Ogdoad”, as shown adjacent, as the primordial creative entity that produced Ra-Atum or the sun god, who in turn made or produced the Ennead. 
The ancient Egyptian water god Nun, in short, expanded into a set of four male-female god pairs, specifically: Nun and Naunet, god and goddess of chaos, Huh and Huhet, god and goddess of space of infinity, Kuk and Kauket, god and goddess of darkness, and Amen and Amenet, god and goddess of invisibility of the winds and of turbulence of stormy waters, both incarnation of hidden powers.
In Hermopolis, it was believed that there was a giant lotus blossom that first emerged from the primordial waters of Nun and from which the sun god came forth.
See main: Thebian creation mythIn 2050BC, Thebes became the new state capital of Egypt, according to which the god Amen was reconceptualized as a fusion or incarnation of all the supreme gods come before. 
See main: God character equivalencesIn Hindu mythology (c.900BC), as popularized in India, a variant of the above, was coded as such that Nun became the god VishNu who associates with a man named MaNu (i.e. Noah variant), who builds a boat before the great flood, and where the Ogdoad becomes the charcter "Sherma", the keme becomes the character "Hama", and god Ptah becomes the character "Jiapheta".
In 700BC, Hermopolis creation myth, with its two primordial god families, i.e. Ogdoad and Ennead, became, via the Greek scholars travelling to Egypt to study under their priests, Hesiod, as detailed in his Theogony (c.700BC), and Homer, in particular, became rewritten such that the Ogdoad became the Greek “primordial deities” (Ѻ) and the Ennead, in a general sense, becomes the god family (Ѻ) of the “Titans” and the “Olympians”, the where the war that famously ensues is the rescript of the famous battle between Set and Horus and on the question of the right to rule over both Upper and Lower Egypt.
Thoth | Hermes | Hermetic
There is, to note, some discussion (Mervat, 2019) of Thoth, in respect Hermopolis, who became the Greek Hermes, and hence to the terms such as “hermetic”. 
See main: God character equivalencesIn c.300BC, in Judaism, as described in the Old Testament in the Bible, the three main Egyptian creation myths: Heliopolis creation myth (3100BC), Memphis creation myth (2800BC), and Hermopolis creation myth (2400BC), as decoded by Gary Greenberg (2000), were assimilated such that (a) the characteristic descriptions of the Ogdoad became the opening paragraph wording of Genesis, and also (b) Nun was rescripted into story of a man named Noah, who lands on a mountain (i.e. pyramids), who has three sons, named in code as: Shem (i.e. Ogdoad), Ham (i.e. keme), and Japheth (i.e. god Ptah), depicted as follows:
● Clay creation myth
● Thebian creation myth
● Amarnan creation myth
1. Thims, Libb. (2016). Smart Atheism: For Kids (pdf | 309-pgs). Publisher.
2. Luckhert, Karl. (1991). Egyptian Light and Hebrew Fire: Theological and Philosophical Roots of Christendom in Evolutionary Perspective (pgs. 97-98). SUNY Press.
3. Nasser, Mervat. (2019). The Path to New Hermopolis (abs). Rubedo Press.
● Hermopolis creation myth (section) – Wikipedia.