Edda
Edda or the plural Eddas or Eddur, including Poetic Edda (or Older Edda) and Prose Edda (or Younger Edda), are two collections of stories about Viking deities. They were made in around 9th to 13th century by Icelandic Christian historians.
Although the Eddur are the most important written records remaining today about Norse mythology, they are not very reliable because Christians hated pagan religions, and they changed the original tales to make the Norse gods and goddesses look silly, lusty, and barbaric.
The term "Edda" most likely refers to Oddi, a place where both Saemund Sigfusson (a cleric who is rumoured author of Older Edda), and Snorri Sturluson (a Christian politician, author of Younger Edda) lived.
Related pages
Saga
Norse mythology