lang

This is what Minecraft uses for languages, one json for each localized language in

📦resource_pack.zip
  └── 📁assets
       └── 📁minecraft
           └── 📁lang
                └── 📑en_us.json

An example of something you could do is to modify an existing name

{
  "block.minecraft.deepslate_tiles": "Deepslate Tiles",
  "block.minecraft.detector_rail": "Detector Rail",
  "block.minecraft.diamond_block": "Block of Diamond",
  "item.minecraft.diamond": "Diamond"
}

the list of all the examples that you can modify for lang can be found here, and the available languages here

You can also create your own lang options and use them in some way

{
	"item.key.iron":"Iron Key",
	"item.key.copper":"Copper Key",
	"item.key.rusty":"Rusty Key",
	"item.key.iron.lore":"Opens Iron Locks",
	"item.key.copper.lore":"Opens Copper Locks",
	"item.key.rusty.lore":"Opens Rusty Locks",
	"link.liminality.click":"Click me!",
	"chat.liminality.join": "Enter the Elevator to Start!",
	"chat.liminality.join_lv3": "Enter the Elevator",
	"chat.liminality.found": "Found the Extit!",
	"chat.liminality.valve": "activated a valve!",
	"chat.liminality.generator": "activated a generator!",
	"text.liminality.start": "START"
}