Guides
The database pages tell you what a thing is. These tell you how the game works around it: what decides a fishing catch, what a house needs before an NPC moves in, how biome spread behaves after the Wall of Flesh, and what the damage numbers on every item page actually resolve to in a fight.
World and biomes
Bee Hive (biome)Biome spreadBiomesChasmsDesertDungeonEnchanted Sword ShrineEvil biomesFloating IslandForestGemcornsGlowing Mushroom biomeGrassesHardmode conversionJungleJungle ShrineJungle TempleLayersLiving TreeMarble CaveMeteorite (biome)OceanPlantsPyramidRuined HouseSnow biomeSpaceSpider NestThe AetherThe CorruptionThe CrimsonThe HallowThe UnderworldTreesUndergroundUnderground DesertUnderground JungleWorldWorld SeedWorld size