Automaton is nothing but a machine which accepts the strings of a language L over an input alphabet Σ.
There are four different types of Automata that are mostly used in the theory of computation (TOC). These are as follows −
When comparing these four types of automata, Finite-state machines are less powerful whereas Turing machines are more powerful.
Note − Deterministic Finite Automata (DFA) and the Non-Deterministic Finite Automata (NFA) have the same power because every DFA is converted into NFA and every NFA is converted into DFA.
So far, we are familiar with the types of automata. Now, let us discuss the expressive power of automata and further understand its applications.
Let’s see the equivalence of each automaton before going to applications of automata.
Finite-state Machine is equivalent to the following −
Pushdown Automata is equivalent to the following −
Turing Machine is equivalent to the following −
The applications of the different automata in Toc are explained below −
Finite Automata (FA)
The applications of Finite Automata are as follows −
Push Down Automata (PDA)
The applications of Pushdown automata are as follows −
Linear Bounded Automata (LBA)
The applications of linear bounded automata are as follows −
Turing Machine (TM)
The applications of Turing machine are as follows −