Buri had a son who was called Bor who married a Giantess named Bestla . She was the daughter of the Giant Bolthorn. They had three sons together, Odin, Vili, and Ve. Bor's sons killed the Giant Ymir and as he fell so much blood flowed from his open wounds that they drowned all of the Frost Giants except for one named Bergelmir, and his family, who escaped a watery death by climbing up onto his lur. It is through his family line that the Frost Giants still exist to this day.
Then the brothers three took Ymir' s body and carried it into the center of Ginnungagap, and made the world from his body, and his "salty blood " became the seas, and lakes. His flesh was used to cover the land, and his bones became the mountains. His jaw, teeth, and broken bones became the rocks and stones that lie about this new world. The brothers then took Ymir' s skull and made from it the sky, and placed it above the earth. The Gods placed a Dwarf under each of the four corners to hold up the sky.
Odin, Vili, and Ve then gathered up the sparks and embers that were floating around after having been blown out of Muspellheim, and placed them in the middle of Ginnungagap to give light to the heavens above, and the earth below. They fixed some of these new stars in the sky, while they allowed others to wander through the heavens. From this moment on sprang forth the understanding of days and years.
The Gods were still not done fashioning the new world and used Ymir's eyebrows to make a stronghold that extended the whole length of the world. This stronghold was to keep out the Giants who had become hostile. ( Probably because the Gods killed Ymir ). They took the Giant' s brains and flung them up into the air and made them into clouds to bring life giving rain to this new world.
Next : A Sun and a Moon, and a Son and a Daughter.
Go with Odin's wisdom, Freyja's love, and Thor's protection !