Computers in Our Lives, Then and Now

You may use computers before you even reach school. Some sit on desks. Others hide inside machines that do everyday jobs.

What makes it a computer?

A computer takes in information, follows instructions and gives a result. Information going in is input. Working with it is processing. The result is output. A program is the set of instructions it follows. People write programs.

A washing machine can have a small computer inside. You choose a wash setting. Its program controls the wash, and the machine cleans your clothes. A computer built into another machine is an embedded computer. Cars, digital watches, microwaves and some toys have them too. A keyboard is not needed.

Follow a trip to the store

Imagine buying a box of cereal. Several computer jobs happen along the way.

1. A sensor notices you near the automatic door. In many stores, a small computer controls its opening.
2. A scanner reads the cereal's barcode, a pattern that identifies it. The checkout computer finds the price and adds it to your total.
3. The card reader sends payment information to the bank.
4. The store records that one fewer cereal box is left. This helps staff order more.

These are four jobs, but they need not use four separate computers. One computer can do several jobs. Also, some automatic doors use simple circuits without a computer.

Look around your community

At a library, a computer records which books people borrow. Traffic lights can use timers or sensors to control when cars move. A bus-stop screen shows arrival information. Doctors find health records on computers. Powerful computers help make weather forecasts.

At home, a phone can send a photo or show a map. At school, computers help you write, draw and share work. A teacher can use one to record attendance. Instant messages and video calls help people far apart keep in touch.

Using computers to store, find, send and work with information is called information technology, or IT.

To explain one use, name the person, the job and the help. For example: “The librarian scans my book. The computer records when I need to return it.” That tells more than “The library has a computer.”

How did people share pictures before phones had cameras? They still took pictures, but the tools and the waiting time were different. You can compare the same activity across time.

Keep the activity the same

A technology is a tool or system people make to do a job. A computing technology uses computers. A then-and-now comparison shows how an activity changed after a technology arrived.

Choose one activity, such as finding your way. Describe the old tools and the new tools. Then ask what became easier, what became harder and who could be left out.

Maps downloaded ahead of time can work without internet. A paper map can still be useful when a battery dies.

Work through keeping in touch

Suppose your grandparent lives far away. Before video calls, you could mail letters or make phone calls. A letter took days to arrive. An answer took more days. Long-distance calls could be expensive.

With a video call, you can see and hear each other right away. It costs little extra if your family already has internet. But both people need a device, a good connection and the skills to use it. A letter is also a keepsake you can hold.

The improvement is clear: seeing each other without waiting for the mail. The difficulty is clear too: someone without internet cannot join that way.

Compare more changes

People once searched library books and encyclopedias for information. Now a computer search can find answers quickly, but some results are wrong. You still need to check what you find.

Film cameras often held 24 or 36 pictures per roll. You waited to see the printed pictures. Digital cameras show a picture at once and can store thousands. Streaming lets you choose when to watch or listen, instead of waiting for a broadcast.

Money changed too. Alongside cash, people now pay by card or phone. In Kenya, a service launched in 2007 helped people send money by text message.

Ask an older person, “How did you call friends at my age?” Their answer can show a way of living you have never tried. Describe what they actually did; people had ways to solve problems before today's devices.

A phone can fit in your hand. Early electronic computers filled rooms. People kept finding ways to make computers smaller and more useful.

From a room to a pocket

ENIAC was finished in the United States in 1945. It filled a large room and weighed about 30 tons, or 27 metric tons. It mainly did math. Today's phones are much faster and do many more kinds of jobs.

Personal computers reached more homes and offices in the late 1970s and 1980s. Laptops made computing easier to carry. Smartphones and tablets put many tools into small devices. Computers also went inside other machines. A talking spelling toy had a small computer in 1978, long before smartphones.

Smaller size was only part of the change. Computers became faster, cheaper and easier to use. More people could get them and use them for daily tasks.

One problem leads to another idea

A limitation is something a tool cannot do well. A phone tied to the wall was useful at home. You could not carry it down the street. Mobile phones helped people call while away from home. Smartphones later added maps, cameras and internet tools.

Letters carried messages over long distances, but took days. In 1971, email was sent between computers over a network. Messages could arrive much faster. Phones later made email and messaging easy to carry with you. Email still works on phones today.

Streaming sends a show or song over the internet while you watch or listen. You do not wait for the whole file first. This lets families choose when to watch many programs.

Think about the next invention

An emerging technology is new, still changing and starting to be used. Delivery drones, self-driving cars and AI chat tools are examples.

In Rwanda, drones have delivered blood supplies to hospitals since 2016. This can help hospitals far from cities get supplies quickly. A delivery drone also needs electricity and safe places to fly. It can make noise near people's homes.

To judge a new idea, ask four questions:

• What problem does it solve?
• Who will it help?
• What new problems could it bring?
• Would I use it? Why?

People choose what to invent and improve. New tools do not make every older tool disappear: paper books, radios and landline phones are still used.

A computer can add a long shopping list quickly. You can notice that a friend needs kindness. Different tasks call for different strengths.

Compare the strengths

A computer does not get bored with repeated work. A person can notice that the task itself needs changing. These strengths can help each other.

A computer can quickly multiply 4,382 by 917. The answer is 4,018,294. A person using paper may need several minutes. But choosing a book to cheer up your sad friend needs knowledge of that friend. A fast calculation cannot supply that care.

Fast work still needs checking

A computer follows its program. It does not fix a mistake just because a person meant something else. A bug is an error in a program. Wrong information going in can also lead to a wrong result. A broken part can cause trouble too.

Imagine a store enters a price as 90 cents instead of 60 cents. The checkout can correctly add the prices it receives. The bill is still wrong because the stored price is wrong. Being quick does not make the information true.

“Garbage in, garbage out” is a reminder to check the information you give a computer. It is not enough to trust an answer because it appeared on a screen.

Share the work

A greenhouse computer can check temperature every minute through the night. A gardener can study the plants and decide what care they need. A doctor uses computer records and scans, then talks with a patient about treatment. A pilot can use autopilot for steady flying and take control when judgment is needed.

AI, short for artificial intelligence, is used in some programs. These tools can recognize pictures or write replies. They can make mistakes. They do not have feelings or care about people. People check their work and make important decisions.

If classmates disagree about a game, a computer could keep score. The children still need to listen, talk and agree on fair rules.

A real robot might be a round vacuum or a factory arm. It does not need a face. Its shape fits the job people built it to do.

Sense, decide, act

A robot is controlled by a computer. It senses something around it, follows a program to decide what happens next, and acts by moving or doing a job.

Follow a robot vacuum:

1. Sense: a bump sensor notices a chair. Another sensor notices a stair edge.
2. Decide: its program follows a rule, such as “Turn after a bump” or “Stop at a drop.”
3. Act: the wheels turn and the brushes spin.

The robot can clean a floor, but socks and cables may trap it. People still pick up toys, empty it and fix it.

On its own or steered?

An autonomous robot uses sensors and a program without someone steering each move. A robot vacuum can move around a room and return to charge this way.

A remote-controlled machine is steered by a person. Think of a toy car that turns when you press its controller. Some robots combine both ways: they do part of a job alone, then a person takes control.

Robots do many kinds of work

Some robots deliver food on sidewalks. Some trains run without a driver on board. Surgeons can control robotic arms for careful movements during operations; the surgeon stays in charge.

Stories can imagine more

Story robots often talk like friends and have feelings. Real robots do not have feelings, even if a screen shows a smile. Most are built for a limited kind of work.

People design, program, power, check and repair robots. As robots take over tasks, some jobs change or disappear. New work also appears in building and looking after the robots.

Someone chose how your favorite game looks and works. Someone else checked its buttons. Technology begins with people noticing a need and making choices.

Start with a person and a problem

A user is a person who uses a tool. Designers find out what users need. Engineers and programmers build the tool. Testers check whether it works. Most technologies grow from teamwork and earlier ideas.

Different needs lead to different tools. Barcode scanners help stores enter prices quickly. Automatic doors help people carrying bags or using wheelchairs. Traffic signals help people and vehicles take turns at busy crossings. Many modern traffic lights use computers and sensors.

People also design for fun, sharing and culture. An app can help children hear a language their grandparents speak. Recorded stories can help a community pass its stories to future children.

Make, test and improve

Designers often follow a design cycle:

1. Find the problem. Learn who the users are and what they need.
2. Think of several ideas.
3. Choose an idea and plan it.
4. Build a first version.
5. Ask real users to try it.
6. Improve it, then test again.

The cycle can go around many times. Testing shows problems that the team did not notice while building.

Work through a school lunch screen

Paper lunch lists keep getting lost. The school wants a screen for choosing lunch. The users include young children and kitchen staff.

The team adds meal pictures, big buttons and a read-aloud button. These help children who cannot read yet. A five-year-old tries the screen. She chooses lunch but cannot find how to finish.

The team adds a large “Done” button with a check mark. Then children test the screen again. The kitchen staff also check that the order list gives them what they need.

Whose needs are missing?

A team that tests only with people like its own members can miss other needs. Different ages, backgrounds and abilities bring useful ideas. Children can design too: you can sketch a game, plan a helpful screen or test whether a button is easy to find.

Many people helped make computing what it is today. They worked in different places and times. Their ideas solved different problems, from doing math to reading web pages.

Instructions and programs

Al-Khwarizmi worked in Baghdad in the 800s, more than 1,100 years ago. He wrote about methods for solving math problems step by step. The word algorithm, meaning step-by-step instructions, comes from his name.

Ada Lovelace, from England, wrote notes about Charles Babbage's planned Analytical Engine in 1843. The machine was never finished. Her notes gave steps for making a series of numbers. These are often called the first published computer program. She also imagined machines working with music.

Grace Hopper was an American computer scientist and Navy officer. She wanted programming to be easier. In 1952, she and her team made A-0, one of the earliest tools called compilers. A compiler translates a programmer's instructions into code a computer can run. Hopper later helped create COBOL in 1959, a language used by businesses and governments.

Check, play and share

Katherine Johnson, a Black mathematician at NASA, checked flight-path calculations. Before John Glenn orbited Earth in 1962, he asked her to check the computer's math by hand. Computers and skilled people checked each other's work.

Jerry Lawson, a Black American engineer, led the engineering team behind the Fairchild Channel F in 1976. This early home game system used swappable game cartridges. Families could change games without buying another machine.

Tim Berners-Lee, from England, proposed the World Wide Web at CERN in Switzerland in 1989. Web pages let people share and follow linked information. Making the web free to use helped it spread.

Open the web to more people

Chieko Asakawa, from Japan, became blind at 14. Many blind people found web pages hard to read and move around in. Working at IBM, she developed Home Page Reader, released in 1997. This talking browser made the web much easier to use.

Her story shows that people with disabilities design technology too. People who face a difficulty can bring strong ideas about fixing it.

To make a pioneer profile, connect the person to a problem and a change. For Asakawa: web pages were difficult to use; a talking browser helped people read and move through them. Explain how the work helped people, not just when it happened. Some pioneers' work, especially that of women and people of color, was left out of many history books for years.

Could everyone in your class use the same game screen? Some children need bigger words. Others need sound shown as text. Accessibility means making something easy to use, including for people with disabilities.

Match the feature to the need

People see, hear, move, think and learn in different ways. About 1 in 6 people worldwide, around 1.3 billion, live with a significant disability.

A screen reader needs useful descriptions for pictures. Simply making the picture bigger does not help someone who cannot see it.

Check a game screen

A game uses red and green for its teams. Some people have trouble telling these colors apart. This affects up to about 1 in 12 boys and men. Add names or shapes, so color is not the only clue.

Next, a beep is the only signal that time is up. A deaf player misses it. Add a clear message or visible timer too. A steady message is useful without needing a flashing effect.

Finally, the buttons are tiny and close together. A player finds them hard to press. Make them bigger and leave space between them. Test each change with the people who need it.

Help can spread

The curb-cut effect means a feature made for one group helps others too. Curb ramps were made for wheelchair users. They also help people pushing strollers or pulling suitcases.

Captions help people who are deaf or hard of hearing. They also help you watch a video in a noisy room. Voice control helps people with limited movement and people whose hands are full. A broken arm can make small buttons difficult for anyone.

Plan for real people from the start

Use clear words and pictures. Let people change text size and speed. Offer sound and a visible signal together. A language setting can help a family member who reads another language best.

Ask people with disabilities to test your ideas. They know their own needs. Planning accessibility early helps the team build the right controls before the whole tool is finished.

You can work with computers and love art, music or stories. Making technology takes many skills. Writing code is one part of the work.

Meet the team

A software developer, or programmer, writes, tests and fixes programs. A game designer plans rules, characters and levels. A user experience designer, often called a UX designer, watches people try a tool and makes it easier to use.

A hardware engineer designs computer parts and devices. A robotics engineer designs, builds and programs robots. A data scientist looks for patterns in large amounts of information, such as weather records.

A cybersecurity specialist protects computers and information from people trying to break in. An IT support technician fixes problems and helps people use their computers.

Follow a game from idea to play

Suppose a team is making a game about an underwater adventure. Each person brings something different.

• The game designer plans how players explore and win.
• The artist draws the sea creatures.
• The programmer writes the instructions that make the game run.
• The sound designer makes music and sound effects.
• The tester tries the game repeatedly to find bugs.
• The producer helps everyone organize their work together.

The team needs to talk. A beautiful picture may hide an important button. A new level may be too hard for the children testing it. Team members share what they notice and solve the problems together.

Computing reaches many places

Computing workers make tools for hospitals, train systems, farms and spacecraft. They can help medical machines run, plan transportation timetables or build crop sensors. Entertainment teams create animations, games and streaming services.

You do not need to fit one picture of a “computer person.” People of different genders, backgrounds and abilities do this work. Patience helps when a bug is hard to find. Creativity helps when a design is confusing. Listening helps a team understand users.

Some tasks need a lot of math; others need strong art, writing or people skills. New tools also create new kinds of work. Smartphone app developers and drone pilots were far less common 30 years ago. The useful habit is to keep learning.

A person can use computers at work without having a computing job. A doctor, farmer or bus driver may use one every day.

What does the computer help with?

People use computers to find information, store records, communicate and create things. A doctor reads digital records. A store owner checks stock. A bus driver follows a route on a GPS screen. An animator makes pictures move with digital tools.

Workers can also share the same file from different places. A team might edit one document, keep a shared calendar or meet by video call. Animators in several cities can work on the same film.

Follow a librarian's changing work

Before computer catalogs, a librarian searched drawers of cards to find books. Due dates were stamped by hand. Finding a book could involve checking several cards.

Now a computer catalog searches quickly. A self-service machine can record your borrowed books. The librarian still helps you choose something to read, runs clubs and teaches people how to check information.

The computer took over some tasks. It did not take over everything useful about being a librarian. Caring about readers and understanding their questions still matter.

Tasks and jobs are different

A task is one piece of work. A job usually contains many tasks. A machine taking one task does not tell you what happens to the whole job.

Self-checkouts change the work of scanning shopping. Robot arms take over some factory tasks. Some jobs need fewer people, and some jobs disappear. Other jobs change, and new ones appear. People must install, program and repair the new tools.

Workers keep learning as their tools change. Teachers learned to teach by video call when many schools closed in 2020. Farmers learned to use GPS-guided tractors. Programmers learn new tools, including AI helpers, and still check the results.

When you hear about a new machine at work, ask what task it does. Then ask what people still do and what new help the machine needs.

A technology can help your family and bring problems too. You can weigh both sides before choosing how to use it.

Make a benefits-and-risks chart

A benefit is something good a tool brings. A risk is a chance of something bad happening. Try these steps:

1. Name the technology.
2. Say who uses it and why.
3. List the benefits.
4. List the risks.
5. Find ways to make the risks smaller.
6. Decide whether it fits your family.

Weigh a smart speaker

A smart speaker can play songs, set timers and answer questions. Voice control can help a family member turn lights on without reaching a switch.

It listens for its wake word. It may wake by mistake and record speech. Its answers can be wrong, and buying it costs money. With a grown-up, check privacy settings. Switching off its microphone when it is not needed can reduce unwanted recording.

A useful feature does not remove its risks. A risk also does not mean that every family must make the same choice.

Leave room for the rest of life

Games can be fun and help you solve problems with friends. They can also be hard to stop, and some ask for money. Online lessons let you learn from far away, but asking questions can be harder.

Long screen sessions can crowd out sleep, exercise and time together. Screens just before bed can make falling asleep harder. A family plan can set times that leave room for other things.

Have a way to carry on

Relying on a device can be risky when the battery dies. Internet trouble can stop online homework or messages. Important phone numbers on paper and a second copy of work can help.

People's needs matter too. Large text on a tablet may help one grandparent read. Another may need patient help learning the controls. Ask who benefits and who needs support, instead of counting only the number of useful features.

Your screen uses electricity. Making the screen used materials and energy too. Even a photo saved online needs real computers somewhere.

Follow a device's life

A device has a life cycle. Metals such as copper, gold, lithium and cobalt are mined. Factories make the parts and put them together. The device travels to a store. Someone uses and charges it. Later it may be reused, recycled or thrown away.

Each stage uses resources and energy. For many phones, making the device causes more harm to the planet than charging it. Keeping a working phone longer avoids making a replacement so soon.

Some electricity comes from burning coal, oil or gas. This adds carbon dioxide to the air and contributes to climate change. Wind, sunlight and moving water make electricity with much less of this pollution.

Count unused electricity

A watt measures how fast a device uses electricity. A watt-hour measures the amount used over time. Multiply watts by hours.

A 100-watt TV is left on for 3 hours daily with nobody watching. First find one day's waste:

That is 300 watt-hours. For seven days:

In a year it wastes 109,500 watt-hours, about 110 kilowatt-hours. There are 1,000 watt-hours in a kilowatt-hour.

Data centers are buildings full of computers. They run websites, store photos and help deliver games, streaming and AI tools. In 2024, they used about 1.5% of the world's electricity. The electricity is used even when those computers are far from you.

Keep devices out of regular trash

E-waste is electrical or electronic equipment people throw away. It includes phones, cables, chargers and battery toys. In 2022, the world produced about 62 million metric tons. That was about 7.8 kilograms, or 17 pounds, per person. About 22% was recorded as properly collected and recycled. Small devices add up: one million phones weighing 200 grams each make 200 metric tons of e-waste.

Dumped or burned e-waste can release harmful materials. Valuable metals are lost too. Batteries in regular trash can start fires. Ask a grown-up to arrange repairs and take old devices or batteries to the right collection points; do not open or burn them.

Use less before recycling

Reduce, reuse, repair, then recycle. Protect a device with a case. Keep using it while it works well. Pass on a working device you no longer need. Use an e-waste collection point when it is finished.

Turn off unwatched screens and sleep or shut down unused computers. Unplug unused chargers. Lower brightness when you can still see clearly. Keep school folders tidy by removing files you no longer need. Log out of shared computers, then shut them down at the end of the day.

Technology can help too. Sensors can switch off empty-room lights. Scientists use computers to study the climate. A video call can replace some journeys.

Before opening an app, ask what you want to do. The best tool depends on the job and the people involved.

Ask five useful questions

• What problem am I trying to solve?
• Is a computer useful, or would a simpler tool work?
• What will it cost in time, money, privacy and energy?
• Does this need kindness, fairness or human judgment?
• Could anyone be left out?

You might choose a digital tool, a non-digital tool or a mix. The choice needs a reason that fits today's task.

Match the tool to the job

A new classmate speaks a different language. A translation app can help you say, “Welcome! Do you want to play?” The tool helps you exchange words. You still show the welcome by including the child.

Now imagine children disagree about the last pizza slice. A computer can count slices. Choosing what is fair needs people to talk and listen.

For multiplication practice, an app can give quick feedback when you work alone. Paper flashcards with a friend need no charged device and give you time together. Both can help you practice.

Think about the person receiving it

You want to send a birthday greeting to a grandparent. A handmade card can be kept and held. A mailed card takes time to arrive. A video message arrives quickly and lets your grandparent hear your voice.

If the birthday is today and your grandparent likes videos, the video message fits. If your grandparent treasures paper cards, making one ahead of time may fit better. “Newest” is not a reason on its own.

Families can choose differently

One family may need voice control because someone finds switches hard to reach. Another may decide the cost and privacy concerns outweigh the help. People can have good reasons for different choices.

With a grown-up, agree on when and where devices are used. Your family might keep dinner free of screens, charge devices outside bedrooms and make time for outdoor play. A working device can stay useful without an upgrade. Turning off an unwatched show saves electricity while leaving your evening free for something else.