What we’ll learn: In this article we’ll learn about Automata, what is automaton, what is the Automata theory and will try to explore more about Automata.

Automata was introduced during 20th century when mathematicians began to develop machines that imitated certain features of man that complete computation much faster and in efficient and reliable way.

Automaton & Automata

Automaton, closely related to the word automation which means a self-operating machine or mechanism and its plural is called Automata.

Automatons are abstract models of machines that performs computation on an input by moving through a series of states or configurations.

Automata Theory

Automata Theory is a study of abstract machines and the computational problems that can be solved using these machines or you can say that automata theory deals with the logic of computation with respect to simple machines, referred to as automata.

Inputs, Outputs and States

Inputs assumed to be sequence of symbols selected from a finite set of input signals.

Outputs are a sequence of symbols selected from a finite set.

States are a finite set whose definition depends on the type of automaton.

Families of Automaton

There are four major families of automaton known as:

  • Finite-state Automata
  • PushDown automata
  • Turning Machine

All of these families are distinguished by the temporary memory:

Finite-state Automata                                                                      Stack

Pushdown Automata                                                                        No TemporaryMemory

Turning Machines                                                                             Random Access Memory


Computation of Automata

Suppose we have a Processor/CPU with whome a memory has been attached, this memory can be input memory, temporary memory or output memory as illustrated below:


1-CPU with which a memory is attached


2- Memory can be in the form of temporary , program, input or output memory.








Lets take an example now to make the idea more clear.

Suppose we have an equation f(x)=x^3

This equation will be solved in the program memory as x * x = x^2 , then the resultant will be again multiplied with the x as x^2*x as shown below:


Suppose a user has now given an input of x=2 as shown in the above figure where x=2 is now in the input memory. Now in the temporary memory all the computations will be held and the resultant will be given to output memory as shown below:

automata 4

Now the question is , what is the Automaton in this entire process? 

So the answer is that the automaton involves only the Processor/CPU and a program memory as shown below. So we will not include input, output and temporary memory in our automaton.

automata 5

So this was a little introduction to Automata and its family members. If you find any trouble related to this article feel free to ask me.