The Vanir are a group of deities in Norse mythology, known for their association with fertility, prosperity, and nature. They are often contrasted with the Aesir, another group of gods who represent order and civilization. The Vanir are believed to have originated from a different realm and are known for their skills in magic and seership. One of the most famous stories involving the Vanir is the Aesir-Vanir War, which was fought between the two groups of gods. After a long conflict, they reached a truce and exchanged hostages, leading to a more harmonious relationship. Key figures among the Vanir include Njord, the god of the sea, and his children, Frey and Freya, who are associated with fertility and love.