Introduction to Computers

Data refers to raw, unorganized facts and figures without context or meaning. Examples

include numbers, symbols, or text such as 85, January, or AB123.

Information, on the other hand, is processed or organized data that carries meaning and can

be used for decision-making. For instance, if we process a list of student scores, the average

or ranking produced becomes information.

A computer is an electronic device that accepts data as input, processes it according to a set

of instructions, stores the results, and produces output in a meaningful form. It operates at

remarkable speed and accuracy, making it an indispensable tool for individuals,

organizations, and governments.

A computer is an electronic device that manipulates data according to a set of instructions (a

program) to produce useful information.

Illustration Example:

When a student enters raw scores into a spreadsheet, the spreadsheet software processes

the data to generate class averages, charts, and reports.

→ Raw data → Process (via CPU and software) → Information output.

Characteristics of a Computer

Computers possess several defining characteristics that distinguish them from other

machines:

1.

Speed: Computers process data and execute instructions millions of times faster than

humans can perform manually.

2. Accuracy: Errors are minimal, and most mistakes result from human input or

programming faults.

Introduction to Computing Instructor: Enoch Haruna Contact: haruna.enoch@nileuniversity.edu.ng

3. Automation: Once programmed, a computer can execute a series of tasks without

further human intervention.

4. Storage Capacity: Computers can store vast amounts of data and retrieve it almost

instantly.

5. Versatility: They can perform a wide range of tasks from numerical calculations to

complex simulations and media processing.

6. Diligence: Unlike humans, computers do not suffer from fatigue or loss of

concentration.

7. Connectivity: Modern computers connect to networks, enabling global data exchange

and collaboration.

These characteristics make computers indispensable in sectors such as finance, health,

education, manufacturing, and government administration.

History and Generations of Computers

The development of computers can be traced back to early counting tools and evolved

through five major generations:

Generation

First

Generation

Period

Technology Used

1940–1956 Vacuum tubes

Examples

ENIAC,

UNIVAC

Key Features

Large size, high power

consumption, slow

processing

Second

Generation

Third

Generation

Fourth

Generation

Fifth

Generation

1956–1963 Transistors

IBM 7094,

CDC 1604

1964–1971 Integrated Circuits (ICs) IBM 360,

PDP-8

1971–Pres

ent

Present

and

beyond

Microprocessors

Artificial Intelligence

(AI), Quantum

Computing

Apple II, IBM

PC

AI-based

systems,

robots

Smaller, faster, more

reliable

Better performance,

multi-programming

Personal computers,

GUI interfaces

Natural language

processing, machine

learning

Each generation marked significant technological progress in terms of speed, reliability, and

usability. The fifth generation continues to evolve with AI, robotics, and neural computing.

Introduction to Computing Instructor: Enoch Haruna Contact: haruna.enoch@nileuniversity.edu.ng

Importance of Computing in Modern Society

Computing has transformed nearly every aspect of human life. Its impact can be observed in:

● Education: E-learning platforms, simulations, and research tools.

● Health: Diagnostic systems, telemedicine, and medical record management.

● Business and Finance: Automation of accounting, data analytics, and e-commerce.

● Government: E-governance, record management, and national databases.

● Science and Engineering: Data modeling, AI-based design, and complex simulations.

● Communication: Social media, instant messaging, and virtual meetings.

In today’s digital world, computer literacy is as fundamental as reading and writing,

empowering individuals to innovate, collaborate, and solve complex problems.

Classification of Computers

Computers can be classified in several ways depending on data handling, purpose, and

size/capacity.

Based on Data Handling

1.

Analog Computers: Process continuous data like temperature or pressure (e.g.,

speedometers).

2. Digital Computers: Process discrete data (0s and 1s); these are the most common type

used in homes and offices.

3. Hybrid Computers: Combine analog and digital features, used in specialized fields like

hospitals or scientific research.

Based on Purpose

● General-purpose Computers: Perform a variety of tasks (e.g., PCs, laptops).

● Special-purpose Computers: Designed for specific applications (e.g., ATMs, embedded

systems in cars).

Based on Size and Capacity

Category

Supercomputer

Description

Extremely powerful; used for weather

forecasting, nuclear simulations

Examples

Cray, IBM Summit

Mainframe

Handles large data processing for organizations

IBM zSeries

Introduction to Computing Instructor: Enoch Haruna Contact: haruna.enoch@nileuniversity.edu.ng

Minicomputer

Microcomputer

(PC)

Smaller than mainframes; used by small

businesses

Personal computers for individuals

Embedded System Built into devices for dedicated functions

DEC PDP-11

Desktops, Laptops

Microwave ovens,

Cars

This classification helps students appreciate how computing power scales from personal

devices to national-level supercomputing systems.

Components of a Computer System

A computer system comprises three main elements: hardware, software, and peopleware.

Hardware

The physical components of a computer system those that can be touched and seen.

Hardware is divided into:

● Input Devices: Keyboard, mouse, scanner, microphone.

● Processing Unit: The CPU, which includes the Arithmetic Logic Unit (ALU), Control Unit

(CU), and registers.

● Output Devices: Monitor, printer, speakers.

● Storage Devices: Hard drives, USBs, CDs, and cloud storage.

Software

Software refers to programs that tell the computer what to do.

● System Software: Includes operating systems (Windows, Linux) that control hardware.

● Application Software: Programs that help users perform specific tasks (MS Word, Excel,

AutoCAD).

● Utility Programs: Maintenance tools (antivirus, file compression utilities).

Peopleware

Peopleware includes all the human components that design, operate, and maintain

computer systems such as programmers, system analysts, IT support staff, and users. Without

peopleware, hardware and software would serve no purpose.

Introduction to Computing Instructor: Enoch Haruna Contact: haruna.enoch@nileuniversity.edu.ng

The Input–Process–Output–Storage (IPOS) Model

The IPOS model explains how data flows through a computer system:

1.

Input: Data is entered using input devices (keyboard, scanner).

2. Processing: The CPU executes instructions, performing calculations and logic

operations.

3. Output: Information is displayed or printed for the user.

4. Storage: Data and information are stored for future use.

Example:

In an ATM transaction:

● Input – The user enters a PIN and withdrawal amount.

● Process – The system verifies the balance.

● Output – The machine dispenses cash and displays confirmation.

● Storage – The transaction is recorded in the bank’s database.