**Difference Between DFA and NFA**

There is not much difference between DFA and NFA because they both accept regular languages. The basic difference in both of these is their transition function is different.

- In DFA, The transition function (δ) takes two arguments (state, symbol) as input and returns
**a single state as output.** - In NFA, The transition function (δ) takes two arguments (state, symbol) as input and
**can return multiple states.**

The following picture explains the differences in both DFA and NFA.

**Difference between DFA and NFA**

The top 10 differences in DFA and NFA are listed below,

SR NO. |
DFA |
NFA |

1 | DFA stands for Deterministic Finite Automata. | NFA stands for Nondeterministic Finite Automata. |

2 | For each sigma value (0, 1…n) there must be a provided path from each state. |
For each sigma value (0, 1…n), there is no need to specify the path from each state |

3 | DFA provides a path for each input, so all digital computers are deterministic. | NFA does not provide a path for each input, so NFA is not used in digital computers. |

4 | There is only one possible transition from one state on the one input symbol. It means multiple choices corresponding to an input are not available. |
There is more than one possible transition from one state on the same input symbol. It means multiple choices are available corresponding to a single input. |

5 | DFA cannot use Empty String. (Epsilon) transition. | NFA can use an Empty String (Epsilon) transition. |

6 | DFA is more difficult to construct and understand. | NFA is easier to construct and understand. |

7 | All DFA are NFA. | All NFA are not DFA. |

8 | DFA requires more space. Because it has normally more states. | NFA requires less space than DFA. Because it usually has fewer states |

9 | Dead State does not in DFA | Dead State may exist in NFA |

10 | Trap State is used in DFA | Trap State is not used in DFA |

**Important points:**

^{n}.- NFA and DFA both can hold more than one final states