The computer is an electronic device that can calculate and process information at great speed.

Tip: choose the version whose length matches your exam — the shorter editions (150–250 words) suit PSC, JSC and SSC, while SSC, HSC and university-admission answers often call for 300–1000 words.

The Computer Paragraph (150 Words)

The computer is an electronic device that accepts data, processes it according to a set of instructions and produces useful output. Charles Babbage is often called the father of the computer for designing the Analytical Engine in the nineteenth century, though the first fully electronic computers appeared in the 1940s. Computers have evolved from room-sized machines to lightweight laptops, tablets and smartphones, and today they pervade every aspect of human life. In education, computers help students research topics, write assignments and access online courses. In medicine, they analyse test results and guide surgical procedures. Businesses use computers to manage accounts, communicate with customers and process transactions. Scientists use them to model climate change, design medicines and explore outer space. However, computers also bring risks: overuse causes eye strain and sedentary behaviour, while cyber-attacks, data theft and online fraud are growing threats. The computer is an indispensable tool of modern civilisation, and learning to use it responsibly is a vital skill for every student.

The Computer Paragraph (200 Words)

The computer is one of the greatest inventions in the history of science and technology. It is an electronic machine that receives data as input, processes that data according to programmed instructions and delivers the results as output. The concept of a programmable computing machine was pioneered by Charles Babbage, who designed the Analytical Engine in the 1830s. The first generation of electronic computers emerged in the 1940s, filling entire rooms and consuming enormous amounts of electricity. Since then computing power has advanced at extraordinary speed: today's smartphones are more powerful than computers that occupied whole floors of university buildings just decades ago. Computers are used in virtually every field of human activity. In education, they enable access to vast digital libraries, online courses and interactive learning tools. In healthcare, computers power diagnostic imaging, patient management systems and medical research. In commerce, they process millions of financial transactions every second and manage global supply chains. In entertainment, they produce animated films, stream music and run video games. Science depends on computers for data analysis, climate modelling and space exploration. In Bangladesh, computer literacy has become a key qualification in the job market, and the government's Digital Bangladesh initiative has expanded computer access in schools and public offices. Despite its benefits, excessive computer use leads to physical problems and exposes users to cybercrime. Every computer user must cultivate safe, purposeful and responsible habits.

The Computer Paragraph (250 Words)

The computer is an electronic device that processes data with extraordinary speed and accuracy, following a set of instructions called a program. The theoretical foundations of modern computing were laid by Charles Babbage and Ada Lovelace in the nineteenth century, and the first fully electronic computers were built in the 1940s. Since then, computers have evolved through several generations — from vacuum-tube machines filling entire rooms to today's ultra-thin laptops, tablets and smartphones that fit in a pocket. This miniaturisation has been driven by advances in semiconductor technology, most famously captured in Moore's Law, which observed that the number of transistors on a chip roughly doubles every two years.

Computers touch virtually every field of human activity. In education, they give students access to digital libraries, educational software, online examinations and multimedia content that makes abstract concepts easier to understand. In medicine, computers analyse X-rays and MRI scans, manage patient records and guide robotic surgery. Banks and businesses rely on computers to process millions of transactions daily and manage global logistics. Scientists use supercomputers to model climate systems, design new drugs and simulate the formation of galaxies. In Bangladesh, computer literacy is now a critical qualification: the information technology sector is a growing source of export income, and the government's Digital Bangladesh vision has installed computers in schools and Union Digital Centres nationwide. However, computers also carry risks: prolonged use causes eye strain, back problems and sedentary habits. Cybercrime, including hacking, phishing and data theft, is a serious and growing threat. Responsible use, combined with regular breaks and up-to-date security software, allows individuals and society to enjoy the computer's vast benefits while managing its dangers.

The Computer Paragraph (300 Words)

The computer is one of the most powerful and versatile tools ever created by human ingenuity. It is an electronic device that accepts input data, processes it at extremely high speed according to stored instructions, retains results in memory and delivers useful output. The intellectual groundwork for modern computers was laid in the nineteenth century by Charles Babbage, who designed the Analytical Engine, and by Ada Lovelace, who wrote what is now regarded as the first algorithm intended for machine execution. The first generation of working electronic computers — such as ENIAC, completed in 1945 — occupied entire buildings and consumed as much electricity as a small town. Advances in semiconductor manufacturing have since made computers progressively smaller, faster and cheaper, resulting in the smartphones and laptops of today that exceed those early giants in power by many millions of times.

The applications of the computer are vast. In education, computers grant learners access to encyclopaedic digital resources, interactive simulations, online examination platforms and distance learning courses. In healthcare, they power diagnostic imaging, electronic patient records, telemedicine and drug-discovery research. Banks and financial institutions use computers to process enormous volumes of transactions instantly and detect fraudulent activity in real time. Engineers rely on computer-aided design to build bridges, aircraft and medical devices. Scientists use supercomputers to model ocean currents, test new materials and search for cures to diseases. The entertainment industry uses computers for film animation, music production, game development and live-streaming. In Bangladesh, the computer has become central to the Digital Bangladesh policy, with labs established in schools and Union Digital Service Centres providing e-government services to citizens in rural areas. The IT and IT-enabled services sector earns significant foreign exchange each year, and computer skills are increasingly mandatory in the job market. Nevertheless, computers also bring problems. Excessive use leads to eye strain, musculoskeletal pain, sleep disruption and physical inactivity. Cybercrime — hacking, data theft, online fraud and ransomware — costs economies enormous sums annually. Addiction to video games or social media through computers harms academic performance and mental health. Responsible computer use, good cyber hygiene and regular physical breaks are essential for every user.

The Computer Paragraph (500 Words)

The computer is an electronic device that accepts data as input, processes it according to a stored program, holds the results in memory and produces them as output. It is considered one of the greatest inventions in the history of science and technology. The concept of a programmable computing machine was pioneered by the English mathematician Charles Babbage, who designed the Difference Engine in 1822 and the Analytical Engine in 1837. Ada Lovelace, working with Babbage, wrote notes now recognised as the first algorithm intended for execution by a machine. The first generation of practical electronic computers emerged in the 1940s: ENIAC, completed in 1945 at the University of Pennsylvania, weighed 30 tonnes, occupied 1,800 square feet of floor space and could perform about 5,000 additions per second — remarkable at the time but laughably slow by modern standards. Advances in transistor technology, integrated circuits and semiconductor manufacturing drove computing power to double roughly every two years, in accordance with the observation known as Moore's Law. The result is today's ultraportable laptops, tablets and smartphones, devices that contain more processing power than was available to entire national governments just decades ago.

Computers permeate virtually every sector of modern life. In education, they enable students to access digital encyclopaedias, interactive simulations, online assessment platforms, video lectures and collaborative tools that make learning more engaging and flexible. Distance education programmes have made university-level courses accessible to learners in remote areas. In healthcare, computers power radiology and MRI imaging systems, electronic health records, telemedicine platforms, laboratory analysis equipment and research databases used in drug discovery. Surgeons use computer-guided robotic systems to perform procedures with greater precision than human hands alone could achieve. In business, computers manage supply chains, process financial transactions, analyse consumer behaviour and run the e-commerce platforms through which enormous volumes of goods are sold each year. In science, supercomputers model climate change, simulate subatomic particle collisions, analyse genomic data and search for habitable planets around distant stars. In the arts, computers are used for film animation, music production, graphic design, video game development and digital photography. In Bangladesh, the computer has assumed strategic importance. The Digital Bangladesh initiative has placed computer laboratories in thousands of schools and installed digital centres at the union level. The information technology and IT-enabled services industry employs a growing number of young professionals and earns significant foreign exchange. Computer literacy is now a baseline requirement in most formal sector jobs. Yet computers are not without drawbacks. Prolonged screen use causes eye strain, dry eyes and myopia, particularly in children. Sitting at a computer for many hours each day contributes to obesity, back pain and cardiovascular risk. Cybercrime — including hacking, phishing, ransomware and identity theft — inflicts massive financial and psychological damage. Addiction to online games and social media through computers impairs concentration and harms academic performance. Responsible computer use involves taking regular breaks, maintaining correct posture, installing and updating security software, using strong passwords and balancing screen time with physical activity and offline interaction.

The Computer Paragraph (800 Words)

Introduction

The computer is arguably the most transformative invention of the twentieth century. It is an electronic device that processes data at extraordinary speed and precision, following a sequence of stored instructions called a program. The theoretical foundations of computing were established in the nineteenth century — Charles Babbage envisioned the programmable Analytical Engine in the 1830s, and Ada Lovelace articulated what is now recognised as the first computer algorithm. The first practical electronic computers appeared in the 1940s, occupying entire rooms and requiring teams of engineers to operate. The subsequent development of transistors, integrated circuits and microprocessors shrank computers from room-sized installations to devices that fit in a shirt pocket, while multiplying their speed and capacity by many billions of times. A modern laptop costing a few hundred dollars is immeasurably more powerful than the supercomputers of thirty years ago. This extraordinary trajectory of improvement has made the computer available to individuals, schools, businesses, governments and scientists worldwide, embedding it in almost every corner of human activity.

Uses of the Computer

The range of computer applications is effectively limitless. In education, computers give students access to digital libraries, interactive simulations, multimedia tutorials and online examination systems. Distance learning platforms allow a student in rural Bangladesh to attend a lecture delivered by an expert in Dhaka or abroad. Teachers use computers to prepare lesson plans, grade assignments and communicate with students and parents. In healthcare, computers operate diagnostic imaging equipment, manage electronic patient records, support robotic surgery and power the bioinformatics research that identifies new medicines. In business and finance, computers handle millions of transactions per second, detect fraudulent patterns, model investment risk and run the e-commerce systems through which global trade increasingly flows. Engineers use computer-aided design and simulation software to test structures, aircraft components and electronic circuits before a single physical prototype is built. Scientists rely on supercomputers to model climate change, simulate particle physics experiments and analyse massive genomic datasets. The entertainment, media and creative industries use computers for film-making, music production, graphic design and video game development. In government and public administration, computers power census data analysis, tax collection systems, land registry databases and national identification systems.

Computers in Bangladesh

In Bangladesh, the computer has gained particular strategic importance under the Digital Bangladesh and Smart Bangladesh policies. Computer laboratories have been established in thousands of secondary schools and colleges, giving students across the country hands-on experience with hardware and software. Union Digital Centres — government-sponsored computer facilities at the lowest tier of local government — allow citizens in remote rural areas to access land records, birth certificates, form applications and other e-government services without travelling to district towns. The IT and IT-enabled services sector has grown rapidly, with Bangladeshi software companies and freelancers earning foreign exchange through web development, data processing, graphics and business process management. Technical institutions now offer computer and ICT courses alongside traditional trades, reflecting the recognition that computer literacy is an essential qualification in the modern economy. E-commerce platforms have enabled Bangladeshi artisans and small manufacturers to sell products online. In healthcare, hospital management systems and telemedicine platforms have improved record-keeping and extended specialist care to underserved populations. The computer has thus become an important vehicle of development in a country that is rapidly modernising.

Disadvantages and Responsible Use

Despite its enormous benefits, the computer poses significant challenges to health, security and society. Prolonged use of computer screens is associated with eye strain, dry-eye syndrome and an increase in myopia, particularly among children who spend many hours each day on screens. Sitting at a computer for extended periods without adequate breaks leads to back and neck pain, repetitive strain injuries and a sedentary lifestyle that increases the risk of obesity and cardiovascular disease. Cybercrime is a serious and rapidly growing threat: hackers, phishers, ransomware gangs and identity thieves exploit vulnerabilities in computer systems and human behaviour to steal data, extort money and disrupt critical services. In Bangladesh, online banking fraud and phishing attacks targeting mobile financial service users are reported frequently. Addiction to computer games and social media platforms is an emerging mental health crisis: affected individuals, predominantly young males, neglect education, personal hygiene and family relationships in favour of screen time. The automation of routine tasks by computer software has displaced workers in many clerical and manufacturing occupations. Finally, the environmental footprint of computing — encompassing energy-hungry data centres, the mining of rare minerals for hardware and the growing problem of electronic waste — is a legitimate ecological concern. Responsible use of computers requires maintaining correct posture, taking regular screen breaks, using strong passwords and updated security software, being sceptical of unsolicited emails and links, setting firm time limits for recreational screen use and disposing of old equipment at approved recycling points.

The Computer Paragraph (1000 Words)

Introduction

The computer stands at the centre of the modern world. It is an electronic machine capable of receiving data, processing it at billions of operations per second according to stored instructions, retaining results in memory and producing output in a form that human beings can understand and use. No single invention of the past century has reshaped human civilisation more profoundly: computers underpin medicine, science, commerce, education, art, governance, communication and national defence. The intellectual history of computing stretches back to the nineteenth century, when Charles Babbage designed his mechanical Difference and Analytical Engines and Ada Lovelace wrote the first description of a computer algorithm. The first generation of working electronic computers appeared in the 1940s — vast, fragile and ferociously expensive machines that occupied entire buildings. The invention of the transistor in 1947, followed by the integrated circuit in 1958 and the microprocessor in 1971, initiated a period of exponential improvement in computing power and exponential reduction in cost and size. Gordon Moore's 1965 observation — that the number of transistors on a chip approximately doubles every two years — described a trajectory that held for over half a century. Its consequences are visible everywhere: a smartphone worth a few hundred dollars today contains more computing power than the world's entire installed base of computers in 1975.

How a Computer Works

Understanding what a computer does requires a basic grasp of its architecture. The central processing unit, or CPU, is the brain of the machine: it fetches instructions from memory, decodes them and executes operations — arithmetic calculations, logical comparisons, data movements — at speeds measured in gigahertz, meaning billions of cycles per second. Random-access memory (RAM) serves as the computer's short-term workspace: fast but temporary storage where data and instructions reside while actively being used. Secondary storage — hard disk drives or solid-state drives — provides longer-term, non-volatile memory where the operating system, applications and files are held when the computer is powered off. Input devices — keyboards, mice, touchscreens, microphones and cameras — allow humans to provide data and commands. Output devices — monitors, speakers and printers — present the results of processing in usable form. The operating system, such as Microsoft Windows, Apple macOS or Linux, coordinates all these components and provides a platform on which application software runs. Networks and the internet allow computers to communicate with one another, multiplying their individual capabilities many times over.

Uses and Benefits of Computers

The applications of computers span every field of human endeavour. In education, computers provide students with access to digital libraries, video lectures, interactive simulations and AI-powered tutoring systems that adapt to individual learning pace and style. Online examination platforms allow fair assessment at scale. In medicine and healthcare, computer-driven diagnostic imaging — CT scanners, MRI machines, digital X-ray systems — saves lives by detecting disease earlier and more accurately than was previously possible. Hospital information systems manage patient records, track medication and coordinate care across departments. Telemedicine connects patients in remote areas with specialists hundreds of kilometres away. In science, supercomputers model climate systems, simulate the folding of proteins (relevant to drug design), analyse gravitational-wave data and search for habitable exoplanets. In business, computers process financial transactions, manage inventory and logistics, analyse consumer behaviour and provide the infrastructure for global communication. Creative professionals use computers to produce films, music, video games and architecture of a complexity unimaginable before the digital age. In governance, computers maintain land registries, conduct census surveys, administer tax collection, issue national identification documents and power the e-government portals that deliver services to citizens. In Bangladesh specifically, the IT and IT-enabled services sector has grown into a significant earner of foreign exchange, computer labs in schools have expanded digital access for young learners, and Union Digital Centres have extended e-government services to the most rural communities.

Disadvantages of Computers

The computer's power also generates serious problems. Health is an immediate concern: prolonged screen time is strongly associated with increasing rates of myopia among children and young adults, eye strain, headaches and dry-eye syndrome. The sedentary nature of most computer work contributes to obesity, back and neck pain, repetitive strain injuries and elevated cardiovascular risk. Psychological health is threatened by digital addiction: some users — particularly adolescent males — develop a compulsive relationship with gaming, social media or online entertainment, neglecting education, physical activity, family life and sleep to the point of clinical disorder. Cybercrime is a pervasive and growing threat: ransomware attacks have disabled hospitals and government agencies worldwide; phishing emails steal banking credentials from millions of victims each year; and identity thieves use stolen personal data to open fraudulent accounts. For Bangladesh, online banking fraud and phishing targeting bKash and Nagad users are specific and documented problems. Privacy is a further concern: computers and the internet generate enormous volumes of personal data — browsing history, location data, purchase records — that are collected and often monetised by corporations with little transparency and inadequate regulation. The automation of routine cognitive tasks by increasingly sophisticated software is displacing workers in accounting, customer service, data entry and some fields of law and medicine, raising questions about technological unemployment and economic inequality. The environmental costs of computing are also significant: global data centres consume roughly one to two per cent of world electricity, and the manufacture of computer chips requires rare minerals extracted under ecologically damaging conditions.

Conclusion

The computer is the defining technology of the current age. Its benefits — to health, to science, to education, to economic development and to human connection — are so great that the challenge is not whether to use computers but how to use them wisely. For Bangladesh, computers represent both an opportunity and an obligation. The opportunity lies in the country's young, digitally curious population, its growing IT sector and the government's commitment to a smart, technology-enabled future. The obligation is to ensure that the benefits of computing are distributed equitably, that the harms — addiction, cybercrime, displacement of workers, erosion of privacy and environmental damage — are honestly confronted and addressed, and that every citizen acquires the digital literacy needed to navigate an increasingly computer-mediated world. Schools must teach not only how to operate computers but how to think critically about the information and systems they encounter online. Cybersecurity must be treated as a national priority. Regulation of data collection and artificial intelligence must keep pace with technological change. And individuals must maintain the habits — regular breaks, strong passwords, scepticism toward unsolicited digital communications, balance between screen time and physical activity — that allow them to use one of history's greatest inventions without being consumed by it.