DFA refers to Deterministic Finite Automaton. A Finite Automata(FA) is said to be deterministic if corresponding to an input symbol, there is a single resultant state i.e. there is only one transition. A deterministic finite automata is set of five tuples represented as,

Where, 
Q: A non-empty finite set of states in the finite control(qo, q1, q2, …). 
Σ: A non-empty finite set of input symbols. 
δ: It is a transition function that takes two arguments, a state, and an input symbol, it returns a single state. 
qo: It is starting state, one of the states in Q. 
F: It is a non-empty set of final states/ accepting states from the set belonging to Q.