We said that automata are a model of computation. That means that they are a simplified abstraction of `the real thing'. So what gets abstracted away? One thing that disappears is any notion of hardware or software. We merely deal with states and transitions between states. The distinction between program and machine executing it disappears. One could say that an automaton is the machine and the program. This makes automata relatively easy to implement in either hardware or software. From the point of view of resource consumption, the essence of a finite automaton is that it is a strictly finite model of computation. Everything in it is of a fixed, finite size and cannot be modified in the course of the computation.