Difference between DFA and NFA in Tabular Form
Contents
DFA and NFA Difference
- NFA is Called a Nondeterministic Finite Automaton. DFA is called a Deterministic Finite Automaton. The Key Difference between DFA and NFA is in the below table.
DFA and NFA Comparison Chart
| DFA | NFA |
|---|---|
| DFA stands for Deterministic Finite Automata. | NFA stands for Non-Deterministic Finite Automata. |
| When processing a string in DFA, there is always a unique state to go next when each character is read. It is because, for each state in DFA, there is exactly one state that corresponds to each character being read. | In NFA several choices may exist for the next state. Can move to more than one state. |
| DFA can not use empty string transition. | NFA can use empty string transition. |
| In DFA we cannot move from one state to another without consuming a symbol. | NFA allows € (null) as the second argument of the transition function. This means that the NFA can make a transition without consuming an input symbol. |
| For every symbol of the alphabet, there is only one state transition in DFA. | We do not need to specify how does the NFA react according to some symbol. |
| DFA can be understood as one machine. | NFA can be understood as multiple title machines computing at the same time. |
| DFA will reject the string if it ends at other than accepting the state | If all the branches of NFA die or reject the string, we can say that NFA rejects the string. |
| It is more difficult to construct DFA. | NFA is easier to construct. |
| DFA requires more space. | NFA requires less space. |
| For every input and output, we can construct a DFA machine. | It is not possible to construct an NFA machine for every input and output. |
| All DFA is NFA. | Not all NFA is DFA. |
| Backtracking is allowed in DFA | backtracking is not allowed in NFA |