How does automata theory describe machines without depending on their physical parts?

Automata theory describes machines abstractly by focusing on their logical principles rather than their physical components, such as gears, wires, or transistors. While these physical parts enable a machine to function, the theory treats an automaton as a set of physically unspecified states, inputs, outputs, and rules of operation.1

By abstracting away the hardware, automata theory allows for the mathematical analysis of what can be accomplished through these logical systems. This approach defines an automaton as a logically defined entity that operates as a sequence of discrete states. For example, a Turing machine is defined by its internal states, a set of symbols, and rules for processing information on a tape, regardless of the specific material used to build it.12

This abstraction yields mathematical systems that resemble logical systems, enabling researchers to prove theorems concerning computability and to model complex processes—such as language parsing or information processing—without needing to account for the specific physical construction of the device.13