Question about Instances' Metatables

So if I have a Part.

And I do print(Part.Name) that will fire the .__index. So that means Part.Name does not exist in the table connected to the metatable. So like where is Part.Name stored?

If I were to write it in Lua.

local Table = {} -- Useless?
local Part = setmetatable(Table, {
	__type = "Instance",
	__namecall = function() return end,
	__tostring = function() return end,
	__metatable = "The metatable is locked",
	__index = function() return end,
	__newindex = function() return end
})

print(Part.Name) -- __index fired
Part.Name = "88" -- __newindex fired

Since __index and __newindex needs to fire the Name propertery cannot be stored in “Tabel” so where is it stored?

Please give answers in code format like above…