What is State Machines?

A state machine is a mathematical model of computation. It is 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 state machine is defined by a list of its states, its initial state, and the conditions for each transition. State machines are used in many areas of computer science including compilers, operating systems, and hardware design.