Which is data and key?, how to sepperate a lot of variable

I want to save this to datastore
local world_UserId_seed_Name_Lchunk_Chunk = {12345678,12345678,12345678,12345678}

I have 2 Question

  1. which is limited by 260.000 characther , i know is data but which is data? and which is key?
  2. i want to save it a lot and i need difference between other , how can i achive it?, i use local world_UserId(from varriable)seed(from varriable)… and so on but it will not work as i guess

Sorry but this is my first time to try Datastore and its made me confused
and sorry if i am bad at english

When working with datastores when you set and get data, you use a key to do so. Don’t use the key to save data. Also do not that the amount of data has been increased to 4 MB meaning much more storage

DataStoreService = game:GetService("DataStoreService")
local datastore = DataStoreService:GetDataStore("test")

-- using a key to get a datastore
game.Players.PlayerAdded:Connect(function(player)

datastore:GetAsync(player.UserId)
-- In this case the player user Id is the key

-- when you set the data first use the key then the data
datastore:SetAsync(player.UserId, {"data here"})

end)

To save use SetAsync or UpdateAsync
And to get use GetAsync