Starting biome. It's the area where you begin the game, and its layout is similar each time: a few bodies of water and caves with plants and numerous Algea. Additionally, you'll find here significant amounts of sand, as well as earth, coal, and copper ore. It's got the most optimal temperatures for your duplicants. This zone is the only one not separated from others by a thick wall of Abyssalite.
Gree/Toxic biome. A very warm area, full of animals, and featuring numerous bodies of water (both polluted and clean). You'll also find geysers and impressive amounts of Slime. That's why the air in this biome is mostly polluted, although there are some pockets of clean air to be found as well. One thing unique to this biome is gold ore, which cannot be found outside of this area.
Purple/Hot. It's one of the hottest, and at the same time most hostile areas for your duplicants. Caves filled with chlorine or hydrogen are a common occurrence. Sometimes, you can encounter Morbs, which transform said gases into polluted air. It's the only area where you can find Bleach Stone and iron ore deposits.
Blue/Winter. This biome is characterized by below zero temperatures. It's separeted from the others with a wall of Abyssalite, which enables it to preserve its conditions. Inside you'll find deposits of ice and snow, which can be melted to obtain water. It's also the only place where you can find Wolframite and several unique plants, such as Sleet Wheat.
Volcanic. It's the hottest biome, always located at the bottom of the map. As the storage of hot magma, it's a great place to convert polluted water into steam or melt other resources.