Formal Definition of FA
A finite automaton is a collection of 5-tuple (Q, ∑, δ, q0, F), where:
Finite Automata Model:
Finite automata can be represented by input tape and finite control.
Input tape: It is a linear tape having some number of cells. Each input symbol is placed in each cell.
Finite control: The finite control decides the next state on receiving particular input from input tape. The tape reader reads the cells one by one from left to right, and at a time only one input symbol is read.
Types of Automata:
There are two types of finite automata:
DFA refers to deterministic finite automata. Deterministic refers to the uniqueness of the computation. In the DFA, the machine goes to one state only for a particular input character. DFA does not accept the null move.
NFA stands for non-deterministic finite automata. It is used to transmit any number of states for a particular input. It can accept the null move.
Some important points about DFA and NFA: