Runeterra (meaning magic earth) is a plane of existence composed of the physical realm: an oblate spheroid planet and the Spirit Realm. It is also the fictional world where most of the lore of the League of Legends intellectual property takes place. Runeterra is part of the larger Runeterra Prime universe.
The currently known continents the planet comprises are Valoran, Shurima and the Camavoran Continent. It also boasts several large bodies of water, such as the currently known 18 Seas (like the Conqueror's Sea and the Guardian's Sea), and 2 Oceans with several archipelagos and islands around them (like Ionia, the Serpent Isles, and the Shadow Isles). The planet orbits around a G-type star while a natural satellite moon orbits around the planet. Runeterra's sun and moon also even mirrored equivalents in the spirit realm.
Magic plays an important part in the history and formation of Runeterra, much like the meaning of the world's name. The origins of magic on Runeterra can be traced back to the creation of the world when the World Runes shaped the planet and gave it life.
There are several types of magic that exist in the universe, primary and combined magics (unofficial names). The Void has no magic at all since it is nothingness. This information is not concrete canon and subject to change.
There are many different species on Runeterra and the other connected realms. Most are divided into sapient, sentient, and non-sentient species.
Unlike Earth, Runeterra has a large number of sapient species. These sapient species can range from being able to use primitive tools to one's advantage to god-like feats like forging literal stars.
Some sentient species are monster-like and aggressive while others less aggressive or tame. While most sentient species are animals, there are instances of plant based sentient species.
Most known instances of non-sentient species are found with plants.
As rich and diverse as Runeterra is, not all species are well documented. From the Shuriman Jungles to the magic wilds of the Ionian Archipelago, known only by names or by visuals, these numerous species are an enigma.