A Deterministic Finite
Automata (
DFA for short) is a computational
device that will either
accept or
reject a given string. Each
state in a DFA
determines the next state, which can only be accessed if the next
symbol to be processed lies on the
edge connecting the
current state to the
next state.
In books on
computational theory, a DFA is written as a
tuple, where each item in the tuple denotes the set of states, the set of symbols the DFA works with (usually a couple letters or numbers to illustrate the concept), a transition function, and the start and accept states.