Freyja (anglicised Freya) belongs not to the Aesir, the family of Odin and Thor, but to the Vanir, a second group of gods associated with fertility, wealth and the sea. Norse myth remembers an early war between the two families, ended by a truce and an exchange of hostages; Freyja, her twin brother Freyr and their father Njord came to live among the Aesir as part of that settlement. She is therefore a goddess of the older fertility powers, brought into the martial world of Asgard rather than born to it.
Her attributes are rich and specific. She owns the necklace Brisingamen, wept tears of red gold, drives a chariot drawn by cats, and possesses a cloak of falcon feathers that lets its wearer fly. She is the goddess most associated with love, desire and fertility, but also, strikingly, with death and battle: half of those who fall in war go not to Odin's Valhalla but to Freyja's hall Sessrumnir in the field Folkvangr. She takes first choice of the slain.
She is also the great practitioner of seidr, the Norse sorcery of prophecy and influence, and the myths say it was Freyja who first taught this magic to the Aesir, including, in some accounts, to Odin himself.