- DFA” stands for “Deterministic Finite Automata.
- In DFA the next possible state is distinctly set.
- DFA cannot use empty string transition.
- Backtracking is allowed in DFA.
- DFA requires more space.
- NFA” stands for “Nondeterministic Finite Automata.”
- In NFA each pair of state and input symbol can have many possible next states.
- NFA can use empty string transition.
- NFA requires less space.
- Backtracking may or may not be allowed in NFA.
but in term of power, DFA is equivalent to NFA.
If there are n states in NFA then equivalent DFA may have at most 2n states.