A finite-state machine (FSM) or finite-state automaton (plural: automata), or simply a state machine, is a mathematical model of computationused to design both computer programs and sequential logic circuits. It is conceived as an abstract machine that can be in one of a finite number of states. The machine is in only one state at a time; the state it is in at any given time is called the current state. It can change from one state to another when initiated by a triggering event or condition, this is called a transition. A particular FSM is defined by a list of its states, and the triggering condition for each transition. Wikipedia 

Finite-state machine

A sketch for Moore Automata Model, which is going to be reduced in process with the help of StateWorks reference.

"Modeling Software with Finite State Machines:
A Practical Approach"

Wagner F., Schmuki R., Wagner T.,
Wolstenholme P.

Publication Date: May 16, 2006
ISBN: 0-8493-8086-3
Number of Pages: 392 
CRC Press

Here is The Theory of Computation Lectures explaining the FSM