Ouranos means the 'sky' or 'heavens',. The son and consort of Gaia, Ouranos fathered the Titans, among others. Hesiod tells how he hated his children and shut them up inside Gaia until Kronos, the youngest child, castrated his father at his mother's request. From the drops of blood which fell onto Gaia/the earth were born the Furies and the Giants. Ouranos' genitals were cast into the sea and from the foam Aphrodite was born.
Apollodorus, Bibliotheca, 1,1 gives a slightly different version: Ouranos threw the Cyclopes, his first children by Gaia, into Tartarus and it was because of this that Gaia incited Kronos against his father. The Furies are the only offspring produced by this event in Apollodorus.
In Hittite mythology, the sky-god, Anu was also castrated by Kumarbi who then swallowed the genitals from which new gods were created.
See Caldwell's introduction to the Theogony, p. 25 and:
Hesiod, Theogony, ed. M.L. West (Oxford, 1966) pp. 20-2