The Old Norse reckoned that there were three races of Gods: the Aesir, the Vanir, and the Jotnar.
The Aesir are those beings most often referred to in the ancient literature simply as "the Gods," in fact the word "As" means "God." They are the Gods of human society, representing things such as leadership, craft, justice, etc.
The Vanir are more closely connected to the earth and represent the fecundity of the land and sea, and the natural forces which help mankind. Once there was a great war between the Aesir and the Vanir, but this was eventually settled when it was determined that neither side could win, and Frey, Freya, and Njord came to live with the Aesir to seal the peace.
The Jotnar are a third race of Gods and at constant war with the Aesir, but there is not and never will be peace in this battle. The Jotnar are never called Gods, but rather referred to as giants. They represent the natural forces of chaos and destruction as the Aesir represent forces of order and society.
Just as fire and ice mix to form the world, this creative interaction of chaos and order maintains the balance of the world. In the end the two sides will meet in the great battle of Ragnarok and the world will be destroyed, only to be reborn.
The Norse notion of the Gods was very much involved with tribalism. The Aesir are the Gods of the tribe or clan. The Vanir are those Gods who are allied with the clan, but who are not part of it. The Jotnar or Giants are the "outlanders" or more simply everyone else.
The Norse Gods were not held to be all powerful or immortal. Their youth was maintained very precariously by the magickal apples of the Goddess Idunna. More importantly at the end of the world a good number of the Gods will die in battle. The Northern view of the world was a practical one with little assurance for the future and little perfection and the Gods are no exception.
It is very important to understand that the Gods are real and living beings. They are not mere personifications of natural forces, nor are they Jungian archetypes that dwell only in our minds--although Jung's work may be helpful in understanding their nature as living beings.
Those divinities who we call "Gods" (i.e., the Aesir and Vanir) are also "personal deities" who take an active interest in the affairs of mankind, and seek relationships with their followers. This is important to remember when we perform ceremonies or pray to the Gods. They aren't magical symbols to be manipulated, nor is our religion some type of giant cosmic vending machine where sacrifices are inserted and blessings come out.
The Gods are living beings and offer us benefits because we are their friends and companions. They should always be treated with respect. (webcom.com)
