Miðgarðr, in Norse mythology, is the realm of humans and is directly translates to "Middle Enclosure." It occupies the central position among the nine realms, with Yggdrasil, the World Tree, connecting it to the other realms.

Midgard is where human beings reside and where their lives unfold, surrounded by the ever-present influence of the gods and the mythological creatures of the Norse cosmos.

Ásgarðr, in Norse mythology, is the celestial realm of the Aesir gods, known for its grandeur and divine splendor. It is positioned above but connected to Midgard, the realm of humans, by the Bifrǫst/Bilrǫst Bridge, a rainbow-colored passage.

Ásgarðr is home to powerful deities like Odin, Thor, and Frigg, who govern the cosmos, shape destinies, and prepare for the cataclysmic events of Ragnarok.

Jǫtunheimr, in Norse mythology, is a realm inhabited by the Jǫtnar, also known as the giants.

It is characterised by its harsh, wintry landscapes, towering mountains and wastelands It is very much a natural realm, existing outside of the governance of the likes of Miðgarðr, Ásgarðr and Vanaheimr.

Jǫtunheimr is often depicted as a place of chaos and conflict, where the giants, powerful and formidable beings, exist in a constant struggle with the gods of Ásgarðr, exemplifying the dualities and oppositions that shape the Norse cosmos.

Vanaheimr, in Norse mythology, is one of the nine realms and is home to the Vanir, a group of deities associated with fertility, nature, and prosperity. It is often portrayed as a lush and vibrant realm, contrasting with the more martial and warlike atmosphere of Asgard, the realm of the Aesir gods.

Vanaheimr and its Vanir inhabitants play a crucial role in the broader cosmology of Norse mythology, including their eventual integration with the Aesir following a war and hostage exchange, symbolising the cyclical nature of alliances and conflicts in the Norse cosmos.

Álfheimr, in Norse mythology, is a realm inhabited by the light elves, known for their radiant beauty and ethereal nature.

It is a realm bathed in perpetual light and is often associated with happiness and luminescence.

While Álfheimr is a relatively lesser-explored realm in Norse mythology, it represents a tranquil and harmonious corner of the cosmos, distinct from the tumultuous worlds of gods and giants.

Svartálfheimr, also known as Nidavellir, is a realm in Norse mythology inhabited by the Svartálfar [dark elves] and also the Dwarves, who are skilled blacksmiths and craftsmen.

It's not clear wether the Dwarves [Dvergr in Old Norse] and the dark elves are one and the same, so for the remainder of this section, I'll refer to them as the dwarves.

This subterranean world is known for its intricate underground caverns and forges where these dwarves create powerful artefacts.

Svartalfheim/Nidavellir plays a significant role in Norse mythology as the birthplace of the legendary hammer Mjǫllnir, wielded by the thunder god Thor, emphasising the importance of craftsmanship and the intricate relationships between the realms in Norse cosmology.

Niflheimr, in Norse mythology, is a frigid and mist-shrouded realm associated with primordial ice and cold.

It stands in stark contrast to Muspelheim, the realm of fire. Niflheimr is believed to be the place of origin for the icy rivers, including the famous Élivágar, the rivers that existed in Ginnungagap at the beginning of the world.

Niflheimr is one of the nine worlds interconnected by the World Tree, Yggdrasil, embodying the elemental forces that shaped the Norse cosmos.

Múspell, in Norse mythology, is a realm of scorching flames and intense heat, ruled by the fire giant Surtr.

It stands in stark opposition to the icy realm of Niflheim, and together, they played a role in the creation of the cosmos.

Múspell is associated with chaos and destruction, and it is destined to clash with the gods during Ragnarǫk, the apocalyptic battle that will engulf the Norse cosmos in flames.

The realm of Hel, also known as Helheim, in Norse mythology, is a haunting and desolate place where the souls of those who did not die in battle reside.

Ruled by the goddess Hel, the half-living and half-dead, it is a realm characterised by eternal cold and gloom. It's also possible that Hel is a place located within the realm of Niflheimr.

Helheim plays a crucial role in the afterlife beliefs of the Norse, representing a destination for the majority of deceased souls, emphasising the stark contrast between the heroic afterlife of Valhalla and the more subdued fate of those who dwell in Hel.