The Overworld is one of the three accessible dimensions, the others being the Nether and the End. The Overworld is where the main character spends most of their time. The Overworld is similar to Earth. There are twelve types of biomes in the Overworld, these being the desert, jungle, forest, mushroom island, tundra, taiga, plains, mesa, savanna, swamp, and the extreme hills biome. Looking at the world size, the Overworld measures to be about 60 Mm by 60 Mm (30 million blocks in each direction from the world's center), giving a surface area of 3.6 billion km2, or about 7 times the area of Earth's 510 million km2.
The Overworld is somewhat similar to Earth, except with mythical monsters such as creepers and giant spiders. The Overworld is by far the most diverse of the three dimensions. The Overworld is the only dimension with water, weather conditions, a large diversity in other plant life and animal life, and a large diversity in minerals and other materials. The Overworld is also the only dimension where time functions properly and mankind has made civilization. The Overworld is also noted to be the only dimension where direction applies, whereas the Nether cannot have a compass function correctly. (unless you use a Lodestone.) The Overworld is also the only dimension that can spawn grass naturally.