In the beginning in Norse mythology, there were two realms of ice and fire.
Niflheim was a realm of mist and ice, and Muspelheim was the realm of fire. Like an existential Oreo, a void was between them and that was called Ginnungagap.
Wherever the two realms met, there was steam and eventually created Ymir, the first being and a giant created from the drops of water, and Audhumla, the first cow.