In Norse mythology, there are nine worlds. These worlds are divided into three main realms: Asgard, the world of the gods; Midgard, the world of humans; and Helheim, the world of the dead. Each realm is also divided into smaller worlds that correspond to different parts of nature and different aspects of life.
In addition, each realm has its own ruler or rulers, as well as its own unique characteristics. The realms can be thought of as parallel dimensions that exist on Earth along with humans. The gods and other supernatural beings can travel between these realms at will.
Odin’s throne room in Asgard contains a golden tree called Yggdrasil that connects all nine worlds together. Vanaheim is ruled by Njord while Nidavellir is ruled by Sindri while Jotunheim is ruled by Utgard-Loki. Midgard was created by Borr who was one of Odin’s sons while Muspelheim was created when sparks flew out from Muspellsheimr which was located in Midgard before it became part of Ymir’s body as well as being named after him since he was born from a spark.
Also, there are Jotunheim (the home of giants), Svartalfheim (the home of black elves), Muspelheim (home to fire demons), Niflhel (a frozen hell where criminals go after death).