# History of Computing Machines

The history of computers is a long and complex one. It started with the invention of the first computer in 1822 by Charles Babbage.

This machine, called the Difference Engine, was designed to interpolate polynomial functions. In 1937, Konrad Zuse created what is known to be the first programmable computer.

He called it Z1, and it was able to calculate square roots, trigonometric functions, and logarithms. The first electronic digital computer was created in 1944 by John Vincent Atanasoff and Clifford Berry.

They called their machine ABC (Atanasoff-Berry Computer). It used vacuum tubes as its main components for computation.

In 1946, ENIAC (Electronic Numerical Integrator And Computer) became operational at the University of Pennsylvania’s Moore School of Electrical Engineering in Philadelphia.

It weighed 27 tons, used 18000 vacuum tubes, consumed 150 kilowatts of power, and could perform 5000 additions or subtractions per second.

With all the advancements in the field of computers, computers can be classified into two major categories.

**Quantum Computers****Classical Computers**

**Classical Computers**

Classical computers are the most widely used type of computer. They are used in everyday life to perform various tasks such as mathematical calculations and data processing.

Classical computers use binary computing, meaning all the data is stored in the form of bits that can logically either be **1 or 0.**

Most processors use x86 architecture which is used in laptops, desktop computers, gaming consoles, arm processors used in smartphones, and a few laptops all use binary computing techniques.

These processors use transistors to store information which can be 1 or 0. Thus, they are all an example of classical computers. Some characteristics of classical computers are as follows.

**Deterministic Calculations**

Classical computers perform deterministic calculations, which means that the results of repeated calculations on the same input are always the same.

**Boolean Algebra**

All operations performed by classical computers are governed by Boolean algebra. Boolean algebra is a branch of maths that deals with operations on binary data either 1’s or 0’s.

**Circuit Behavior**

The laws of classical physics define the circuit behavior of classical computers.

**Error Rates**

Classical computers have relatively lower error rates.

**Quantum Computers**

Quantum computers are a newly emerging type of computer that utilize quantum computing to solve complex problems which cannot be solved through classical computers.

Rather than using binary bits to store data, quantum computers use Qubits to store data. Quantum bits are the most basic unit of quantum computation.

One quantum bit can hold a maximum of two binary bits, which means that a quantum bit can be 0 and 1 simultaneously; this property of qubits is known as superposition.

Some additional characteristics of quantum computers are following

**Probabilistic Calculations**

Calculations performed by quantum computers are probabilistic in their natural meaning that for the same input, the output can vary for the same calculations.

**Linear Algebra**

All operations performed by quantum computers are governed by rules of linear algebra over Hilbert Space. Hilbert space is an inner product space with many applications in quantum mechanics.

**Circuit Behavior**

The laws of quantum mechanics define the circuit behavior of quantum computers.

**Error Rates**

Quantum computers have relatively high error rates.