In the theory of computation

Theory of computation

In theoretical computer science, the theory of computation is the branch that deals with whether and how efficiently problems can be solved on a model of computation, using an algorithm...

 and automata theory

Automata theory

In theoretical computer science, automata theory is the study of abstract machines and the computational problems that can be solved using these machines. These abstract machines are called automata...

, a deterministic finite state machine—also known as deterministic finite automaton (DFA)—is a finite state machine

Finite state machine

A finite-state machine or finite-state automaton , or simply a state machine, is a mathematical model used to design computer programs and digital logic circuits. It is conceived as an abstract machine that can be in one of a finite number of states...

 accepting finite strings of symbols. For each state, there is a transition arrow leading out to a next state for each symbol. Upon reading a symbol, a DFA jumps deterministically from a state to another by following the transition arrow. Deterministic means that there is only one outcome (i.e.