Chaos has been described as the great void of emptiness within the universe from which Eros came and it was he who gave divine order and also perfected all things. In later times it was written that Chaos was a confused shapeless mass from which the universe was developed into a cosmos, or harmonious order. For instance, Hesiod's Theogony says that Erebus and Black Night (Nyx) were born of Chaos, and Ovid the Roman writer described Chaos as an unordered and formless primordial mass. The first Metomorphoses reads, "rather a crude and indigested mass, a lifeless lump, unfashioned and unframed, of jarring seeds and justly Chaos named."
Chaos is from the Greek word Khaos, meaning "gaping void". There are many explanations as to who or what Chaos is, but most theories state that it was the void from which all things developed into a distinctive entity, or in which they existed in a confused and amorphous shape before they were separated into genera. In other words, Chaos is or was "nothingness." Though some ancient writers thought it was the primary source of all things, other writers tell of Gaia (Earth) being born from Chaos without a mate, along with Eros and Tartarus. Then from Gaia came Uranus (Heaven or Sky) which gave us Heaven and Earth.
The Roman writer Ovid gave Chaos its modern meaning; that of an unordered and formless primordial mass.