Machines
From BurnZero
A machine is an enclosure which contains independent parts that exert force on each other to produce a desired function. This may be as simple as cogs in a drill press making holes or more complicated like employees working in a corporation to make profit.
It is the commonality of the parts which define the machine i.e. the majority of parts in a drill press do simple tasks which work together to make holes in things. Whereas in a corporation a collection of people work together to make profit. Machines always have inputs, a function and then based on their efficiency, a productive output (internality) and a waste output (externality).