Minecraft wiki entry for Custom_world_generation, associated text: Noise settings are for generating the shape of the terrain, stored as JSON files within a data pack in the path data/<namespace>/worldgen/noise_settings, and are used with the minecraft:noise generator in the dimension folder. Default settings include minecraft:overworld for normal Overworld generation, minecraft:amplified for Amplified Overworld generation, minecraft:nether for regular Nether generation, minecraft:caves for Cave (Nether-like generation but with Overworld terrain features) generation, minecraft:the_end for regular End generation, and minecraft:floating_islands for Floating Islands (similar to The End outer islands) generation.