Lua: Modules
A module is code that can be loaded using the require function. This code
needs to create and return a table. The functions and constants that the module
wishes to export get defined in this table. This table acts as a namespace.
Standard Libraries
The standard libraries are implemented as modules. You could do this:
local m = require "math"
print(m.sin(3.14))
As a convenience, The stand-alone interpreter loads all standard libraries using the name of the module as the variable name. E.g.:
math = require "math"
string = require "string"