"All the Volvas are
all the vitki
all the seiðrfolk
all the Jötuns
come from Ymir" 
Magic Folk of the North
In Norse and Germanic society, supernatural influences were much feared and respected. As were the people that could manipulate these. There were those within society that could commune with the spirits and deities, forsee the future, alter or influence a person's luck or fortune, bless, curse, heal, influence the weather, and enchant people. Some lived within the villages and served a role similar to that of a shaman. Others distanced themselves from society, instead travelling and offering their services.
These people were usually women and were described in the Eddas as Völvur(Icelandic, plural of Völva) or Seiðkonur (Icelandic, plural of Seiðkona). Other terms have been given to these folk, including Spákona or Spækona (used for one who "speaks", i.e. gives prophecies) and sometimes Vísendakona (Wise woman).
Other terms applied to magical workers throughout Norse mythology includeSeiðskratti (an "evil" sorcerer), Galdramaðr or Galdrakarl (galdr man), Galdrasnót(galdr woman) Gýgr, Fála, Hála, and Skaas (witch), Heiðr, Fjölkyngiskona, andVitka (sorceress), Tauframaðr (charm-man), and myrkriða (a rider of Darkness) .
This is not a comprehensive list, and there are dozens of terms and kennings used in the Norse mythology to name those that practice magical arts.