Introduction

The human race developed computers so that it could perform intricate operations, such as calculation and data processing, or simply for entertainment. Today, much of the world’s infrastructure runs on computers and it has profoundly changed our lives, mostly for the better. Let us discuss some of the characteristics of computers, which make them an essential part of every emerging technology and such a desirable tool in human development.

1. Speed: Computers process data at incredibly high speeds, executing millions or even billions of instructions per second. They can complete tasks in just seconds that would take a human days or even years. We measure a computer’s speed in megahertz (MHz), where one MHz equals one million instructions per second. Today, powerful computers perform billions of operations every second.
2. Accuracy: Besides being efficient, computers also deliver high accuracy. Their level of accuracy depends on both the instructions given and the type of machine used. Since a computer follows only the instructions it receives, incorrect input or faulty commands can lead to incorrect results—a concept known as GIGO (Garbage In, Garbage Out).
3. Diligence: A computer, as a machine, never suffers from human limitations like tiredness or lack of concentration. Even if it has to perform four million calculations, it completes the final, four-millionth one with the same speed and accuracy as the first.
4. Reliability: Generally, we measure a computer's reliability by evaluating its performance against predetermined operational standards without failure. Computers remain highly reliable mainly because their hardware functions independently, without needing human intervention during processing. Moreover, built-in diagnostic features continuously monitor the system to ensure smooth operation.
5. Storage Capability: Computers store large amounts of data and recall required information almost instantly. Since the main memory holds only a limited amount of data, computers use secondary storage devices such as magnetic tapes or disks to store the rest. When needed, the system quickly accesses small sections of data from these storage devices and transfers them into the main memory for processing.
6. Versatility: Computers demonstrate great versatility. They can perform multiple tasks simultaneously with equal ease. For example, you can use a computer to draft a letter, play music, and print a document—all within moments of each other. This flexibility becomes possible by simply changing the program or instructions the computer follows.
7. Resource Sharing: In the early stages of development, computers operated as isolated machines. However, with the rapid advancement of technology, computers now connect and communicate with one another. This connectivity enables users to share expensive resources like printers. Beyond hardware sharing, computers also exchange data and information, helping to build vast networks of knowledge and collaboration.

Although computers reduce the effort required for processing, the task still consumes time and money. Sometimes, a program functions properly for a while but then suddenly produces errors. Rare event combinations or incorrect user instructions usually cause these issues. Users must regularly check and maintain computer components to ensure accurate results. They should place computers in dust-free environments. Since heavy processing heats up components, users must control the system’s ambient temperature to prevent overheating.

THINGS TO REMEMBER

Limitations of a Computer

Sand Tables

In ancient times, people used their fingers to perform basic calculations such as addition and subtraction. Even today, simple calculations are sometimes done using fingers. Soon, humans realized that using pebbles made calculations easier than relying on fingers. Consequently, pebbles began to represent numbers, which led to the development of sand tables. These are known to be the earliest devices used for computation.

A sand table consists of three grooves in the sand with a maximum of 10 pebbles in each groove. To increase the count by one, a pebble has to be added in the right hand groove. When ten pebbles were collected in the right groove, they were removed and one pebble was added to the adjacent left groove. Afterward, sand tables were modified extensively and these modifications resulted in a device known as Abacus.You can see the below image of abacus.

 

Abacus

The abacus, invented around 5,000 years ago in Asia Minor, remains in use in some parts of the world. The term "abacus" is derived from the Arabic word abaq, meaning "dust." Early versions were simple sand-covered boards used for calculations. The modern abacus consists of a wooden frame divided into two parts: an upper deck and a lower deck. Each wire in the upper section has two beads, while each in the lower has five. In the upper deck, a bead moved toward the central bar represents 5; in the lower deck, each bead moved toward the bar represents 1. Users perform arithmetic operations by sliding the beads along the wires, making it one of the earliest tools for manual calculation.

Napier Bones

In 1614, a Scottish mathematician, John Napier, made a more sophisticated computing machine called Napier bones. This was a small instrument made of 10 rods, on which the multiplication table was engraved. It was made of strips of ivory bones, and so the name Napier bones.This device enabled multiplication in a fast manner, if one of the numbers was of one digit only (for example,6 × 6745). Incidentally, Napier also played a key role in the development of logarithms, which stimulated the invention of ‘slide rule’ that substituted the addition of logarithms for multiplication. This was a remarkable invention as it enabled the transformation of multiplication and division into simple addition and subtraction.

Slide Rule

The invention of logarithms influenced the development of another famous invention known as slide rule. In AD 1620, the first slide rule came into existence. It was jointly devised by two British mathematicians, Edmund Gunter and William Oughtred. It was based on the principle that actual distances from the starting point of the rule is directly proportional to the logarithm of the numbers printed on the rule. The slide rule is embodied by two sets of scales that are joined together, with a marginal space between them. This space is enough for the free movement of the slide in the groove of the rule.

The suitable alliance of two scales enabled the slide rule to perform multiplication and division by a method of addition and subtraction.

Pascaline

In 1623, Wilhelm Schickard invented the “Calculating Clock,” a device that could add and subtract and rang a bell to indicate an overflow. His invention later influenced the development of the Pascaline. In 1642, French mathematician, scientist, and philosopher Blaise Pascal created the first functional automatic calculator. He designed it with a complex system of wheels, gears, and numbered display windows. A series of dials attached to numbered wheels (from zero to nine) operated the device. Each full turn of a wheel advanced the one to its left, and indicators above the dials displayed the correct answer. However, this calculator could only perform addition and subtraction.

Stepped Reckoner

In 1694, German mathematician Gottfried Wilhelm von Leibniz extended Pascal’s design to perform multiplication, division, and square root calculations. He called this machine the Stepped Reckoner. It became the first mass-produced calculating device, designed to perform multiplication through repeated addition. Instead of using interconnected gears, Leibniz operated it with a cylinder of stepped teeth. However, the device suffered from a lack of mechanical precision and did not perform reliably.

Punch Card System

Joseph Marie Jacquard, a French textile weaver, used the principle of the weaving process to represent the two digits of the binary system. Jacquard took a large step in the development of computers when he developed punch cards to increase rug production. In 1801,Jacquard invented a power loom with an automatic card reader known as punch card machine. The idea of Jacquard to use punched cards was to provide an effective means of communication with machines. He automated the process with the use of punched cards and placed them between the needles and the thread. The presence or absence of a hole represented the two digits of the binary system, which is the base for all modern digital computers.

 

Difference Engine

In 1822, Charles Babbage, a professor of mathematics, devised a calculating machine called the Difference Engine, which mechanically generated mathematical tables. He designed it to solve differential equations as well. One can view the Difference Engine as a highly complex form of the abacus. However, Babbage never completed a fully functional version. In 1833, he abandoned the project to focus on developing the Analytical Engine.

Analytical Engine

Charles Babbage designed the Analytical Engine, which many consider the first general-purpose programmable computer. Unlike the Difference Engine, it tested a number’s sign and took different actions based on the result, enabling branching in programs. It also controlled the flow of punched cards. Lady Ada Lovelace, a skilled mathematician, collaborated with Babbage by writing articles and programs for the machine, earning her recognition as the "first programmer." Although Babbage never completed the engine, his design introduced core concepts of modern computers—input/output, storage, processing, and control.

Hollerith’s Tabulator

Herman Hollerith invented the punched-card tabulating machine to process the data collected in the United States’ census. This electronic machine was able to read the information on the cards and process it electronically. It consisted of a tabulator, a sorter with compartments electronically controlled by the tabulator’s counter and the device used to punch data onto cards. This tabulator could read the presence or absence of holes in the cards by using spring mounted nails that passed through the holes to make electrical connections. In 1896, Hollerith founded the Tabulating Machine Company, which eventually became known as IBM (International Business Machines).

Other Developments

In the process of the development of computers, many scientists and engineers made significant advances.

1. In 1904, Sir John Ambrose Fleming developed the first thermionic valve, also known as a vacuum tube. He based his invention on Thomas Edison’s observation—later called the “Edison effect”—which described how early light bulbs darkened over time. Recognizing this phenomenon, Fleming created the first rectifier and named the device a “valve” because it allowed electric current to flow in only one direction. This two-element vacuum tube, also called a diode, became the foundation of first-generation computers.
2. In 1906, American inventor Lee de Forest introduced a third electrode into the vacuum tube diode. This modification created the triode, which functioned both as an amplifier and a switch. Its ability to act as a switch had a tremendous impact on the development of digital computing.
3. In 1931, American electrical engineer Vannevar Bush built the differential analyzer to solve differential equations. However, the machine proved cumbersome because it relied on drive belts, shafts, and gears to measure movements and distances.
4. In 1938, Claude Shannon, a student at MIT, recognised the connection between electronic circuits and Boolean algebra. He transferred the two logic states to electronic circuits by assigning different voltage levels to each state. Shannon also provided electronic engineers with the mathematical tool they needed to design digital electronic circuits. These techniques remain the cornerstone of digital electronic design to this day.

Conclusion

It is crucial for understanding computers, features are the key to appreciating how our lives change with them. Their characteristics include speed, precision of work, size of storage memory, automation level, multitasking ability and universality as well as their connectivity and scalability that makes computers irreplaceable in the contemporary world. These features will only evolve as technology does, allowing computers to handle even more sophisticated operations and, in turn, defining life in the 21st century.