Datapacks for Minecraft Java — page 106

A datapack changes the game's rules without touching its code: crafting recipes, loot tables, world structures, advancements, command functions. The game supports all of this natively since 1.13, so a datapack needs neither Forge nor Fabric — it's installed into a specific world and works on the vanilla client and a regular server.

Data packs do different jobs: some change world generation — biomes, terrain and structures, others add mechanics, challenges and horror events, and others are made for servers — economy, ranks, command-based minigames. Generation applies only to new chunks, so such packs are added when a world is created. On Millida Hosting a data pack goes onto the server with the On a server button on its page.

That's the main difference from mods: a datapack doesn't show up in the mod list, and it can't add anything the game doesn't have at all — you can't make a new block with its own model this way. On the other hand, it doesn't clash with other packs, doesn't need updating when you switch loaders and doesn't stop you from playing with friends on a regular server. Installing a datapack is simple: put the archive in the datapacks folder inside the world folder, then reload the world or run the reload command. The card lists the game version, author and license, and all releases are gathered in one place.