Dalswin Life & Business Institute · Class 09

Introduction to Computers

Week 1 · Lesson 1 — what a computer is, what it does with information, and the types you will meet at home and at work.

Beginner 2½ hours Week 1 · Day 1 Reading · Slides · Practice · Quiz

Learning objectives

By the end of this lesson, you can…

Explain what a computer is — and why it is more than a screen and keyboard.
Describe the four jobs every computer performs: input, processing, output and storage.
Recognise computers at work in offices, shops, schools, clinics and banks.
Identify the main types of computers and their strengths and limits.
Choose an appropriate device for a workplace task and give reasons.

The big idea

What is a computer?

An electronic machine that accepts data, processes it using instructions, produces information, and can store it for later.

It follows a program — it does not think for itself.
It works with data: numbers, words, images and sound.
It can repeat the same task quickly and accurately.

The shape does not define the computer. The four jobs do.

Desktop computer, laptop, tablet and smartphone on a desk.

Clearing up a myth

The monitor is not the computer

The screen only shows output. The computer may be under the desk, inside the screen, or in your hand.
A desktop separates the case, monitor, keyboard and mouse.
A laptop combines them in one foldable case.
A phone is a complete computer that also makes calls.
An embedded computer is hidden inside another machine.

Ask yourself: where are the four jobs happening? That is where the computer is.

The information cycle

Every computer does four jobs

InputData goes in — keyboard, mouse, touch, voice, scanner.

ProcessingThe processor follows instructions: calculate, sort, check.

OutputThe result appears on screen, paper or speakers.

StorageThe result is kept for later, even after power off.

Putting it together

The information cycle

Step 1

Input

Data enters the system.

Step 2

Process

Instructions turn data into information.

Step 3

Output

The result is presented to the user.

Storage saves the result and brings it back later as new input.

Data vs information

Data becomes information

Data Raw facts with no meaning yet.

24 · 18 · 30 · 30

Daily attendance figures for one week.

Information Data processed into something useful.

Average 25.5

Weekly average attendance — useful for a report.

A computer’s value is turning raw data into information people can act on.

Why it matters

Why employers expect computer skills

Accurate records — stock, sales, attendance, patients, customers.
Faster reporting — totals and summaries in minutes, not hours.
Professional communication — clear email and documents.
Research and planning — finding reliable information online.
Confidentiality — protecting personal and business data.

Computers support good judgement. They do not replace it.

A professional woman working on a laptop in a bright office.

Computers at work

Computers are everywhere at work

Workplace	What computers do	Typical device
Office	Letters, reports, email, spreadsheets	Desktop, laptop
Bank	Accounts, transfers, statements, fraud checks	Desktop, server
Clinic	Patient records, appointments, test results	Desktop, server
Shop	Sales, stock, receipts, customer records	Till, tablet
School	Registers, results, lesson materials	Laptop, desktop
Farm	Records, prices, weather and sensor data	Smartphone, tablet

Types of computers

Different shapes, same four jobs

DesktopFixed desk workstation; best value for screen and power.

LaptopPortable all-in-one; full keyboard and screen.

TabletTouch-first; good for counters, forms and reading.

SmartphonePocket computer; communication on the move.

ServerShared services and storage for a network.

EmbeddedA hidden computer controlling another machine.

Also: workstations for demanding professional work and mainframes for very large transaction systems.

Compare

Desktop or laptop?

Factor	Desktop	Laptop
Portability	Fixed on a desk	Carried anywhere
Power for price	Usually better value	Pays for portability
Screen and keyboard	Large and comfortable	Smaller, built in
Repair and upgrade	Easier	Harder, often sealed
Best for	Reception, labs, fixed offices	Field staff, students, travel
Watch out	Needs mains power	Theft, battery wear, heat

Pocket and touch

Smartphones and tablets are computers

Smartphone A pocket computer with a mobile network.

Email, maps, mobile money, photos
Great for quick communication
Awkward for long reports and spreadsheets

Tablet A larger touchscreen computer.

Counters, field forms, reading
Simple to use with a finger
Slower for heavy typing; fewer ports

Do not judge a computer by its size. Judge it by the job it can do.

High-performance

When the work is demanding: workstations

A workstation is a high-performance desktop built for professional tasks that need sustained processing, memory and graphics power.

Video editing and animation
Graphic design and engineering
Large data analysis and CAD

Expensive, fixed, and usually paired with specialised software.

Typical user Video editor, designer, engineer, data analyst. Not for Basic typing, email and light browsing — a normal desktop is enough.

Shared computing

One computer, many users: servers

A server provides files, email, websites or databases to other computers over a network.

File serverShared folders for staff documents and records.

Email serverStores and delivers company email.

Web serverHosts websites and online services.

Servers need backups, security and an administrator. They are not used at a desk.

Hidden computers

Computers inside everyday machines

An embedded computer is built inside another machine to control it. It has one dedicated job.

Washing machineControls water level, temperature and spin.

CarManages engine timing, brakes and sensors.

ATMVerifies cards and processes transactions.

Traffic lightTimes the sequence of signals.

Clinic deviceMeasures and displays a patient reading.

Smart TVStreams apps and processes video.

Specialist

Very large systems: mainframes

A mainframe is a very large, powerful computer that handles enormous numbers of transactions at the same time.

Banks — millions of account transactions
Airlines — bookings, schedules and payments
Government — national records and services

They live in secure data centres and are managed by specialists. You will meet their services through a normal desktop or phone.

At a glance

Comparing the main types

Type	Portable	Relative power	Typical use
Desktop	No	High	Fixed office work
Laptop	Yes	Medium–high	Mobile professional
Tablet	Yes	Medium	Counters and field forms
Smartphone	Yes	Low–medium	Communication on the move
Workstation	No	Very high	Design, video, engineering
Server	No	Very high (shared)	Shared files and services
Embedded	Built in	Low, dedicated	Controlling a machine
Mainframe	No	Extremely high	Banking and national systems

Choose the tool

Which device fits the job?

Receptionist at one deskDesktop — large screen, comfortable keyboard, best value.

Field sales officerLaptop — portable, full keyboard, runs office software.

Café counter ordersTablet — simple touchscreen at the counter.

Clinic shared recordsServer — central storage and services for staff computers.

Ask: Where is it used? What software is needed? Who uses it? Is it portable or shared? What is the budget?

Quick check

Three questions before we finish

1. Is a smartphone a computer? Give one reason.

2. A clinic needs shared records for six staff computers. Which type of computer is best?

3. Why is the monitor not the computer?

Discuss with the person next to you. Then complete the quiz on your own.

Key takeaways

What to remember

A computer accepts data, processes it, produces information and stores it.
Desktop, laptop, tablet, phone, workstation, server, embedded and mainframe are all computers.
Choose a device by the task, location, users and budget — not by size or price alone.
Computers support accurate records, clear communication and faster decisions.

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