Gylfaginning gives the main narrative of Ragnarok in Snorri Sturluson’s Prose Edda.
The Prose Edda is divided into four main parts: Prologue, Gylfaginning, Skáldskaparmál, and Háttatal. Gylfaginning, whose title is commonly translated as “The Tricking of Gylfi,” presents a framework in which the legendary Swedish king Gylfi questions three mysterious figures about the Norse gods and the structure of the cosmos.
Near its conclusion, the section describes the signs preceding Ragnarok, the final battle, the deaths of major gods, the destruction of the world, and its subsequent renewal. The narrative is written in prose but includes quotations and references to older skaldic and Eddic poetry.
Gylfaginning is not itself the name of Ragnarok. It is the section of the Prose Edda that contains Snorri’s extended mythological account. Skáldskaparmál instead focuses mainly on poetic language and mythological explanations useful to poets.