Also, your definition of "Global variable" is wrong.
Lua Code:
someVar -- global variable
local someVar -- local variable to file scope
function MyFunc() -- global function
local function MyFunc() -- local function to file scope
-- addonName is the string name of your addon, like "BigWigs" or "My Awesome Addon"
-- addonData is the private table passed to each Lua file within the same addon. useful for things like localization through multiple Lua files
-- ... is a variable argument, or vararg
local addonName, addonData = ...