Unit 1 · Session 3

Data Representation and Applications of Computers

IT 231: IT and Applications (BBA)

Today's focus

Data and Program Representation in a Computer
Applications of Computers in Modern Society

Data and Program Representation in a Computer

Learning Objectives 🎯

By the end of this session, you will be able to:

✅ Explain why computers use the binary system.
✅ Define bit and byte.
✅ Understand the purpose of character encoding standards.
✅ Differentiate between ASCII and Unicode.

Why Binary? 💡

Computers don't understand words. They understand electricity.

At the most basic level, a computer circuit can be in one of two states:

ON (electricity is flowing)
OFF (no electricity)

We represent these two states using numbers:

ON = 1
OFF = 0

This two-digit system (0 and 1) is called the Binary System, and it's the fundamental language of all digital computers.

Try It: Binary Switches

Click each circuit switch. Watch how ON maps to 1 and OFF maps to 0.

Binary digits: 0000

Each switch = one binary digit (bit)

Bits and Bytes: The Building Blocks

All data (text, images, sound) is broken down into these simple units.

Bit (Binary Digit)

The smallest possible unit of data.

0 or 1

Byte

A group of 8 bits.

01000001

A single byte can represent 256 (2⁸) different values.

Try It: Build a Byte

Click the 8 bit buttons to flip them. See the decimal value of the byte you build.

2⁷2⁶2⁵2⁴ 2³2²2¹2⁰

Decimal value: 0 / 255 max

Measuring Data Storage 📊

The byte is the standard unit for measuring digital storage.

Kilobyte (KB) ≈ 1,000 bytes
(A plain text email)
Megabyte (MB) ≈ 1 million bytes
(A high-quality photo or MP3 song)
Gigabyte (GB) ≈ 1 billion bytes
(A standard-definition movie)
Terabyte (TB) ≈ 1 trillion bytes
(The storage of a typical modern laptop)

Quiz: Match the Data Unit

Select the correct storage unit for each scenario, then check your answers.

Scenario	Your Answer
A plain text email
A high-quality photo or MP3 song
A standard-definition movie
A typical modern laptop's full storage

Representing Text: The Challenge

How does a computer understand the letter 'A' or the symbol '?'

It uses Character Encoding Standards: a dictionary that maps each character to a unique binary number.

'A' ➡️ [Encoding Standard] ➡️ 01000001

The First Standard: ASCII

ASCII (American Standard Code for Information Interchange)

An early, widely adopted standard.
Uses 7 or 8 bits per character.
Can represent 128 characters:
- Uppercase English (A-Z)
- Lowercase English (a-z)
- Numbers (0-9)
- Common punctuation (!, @, #, etc.)

Example: In ASCII, the character 'A' is represented by the number 65, which is 01000001 in binary.

Try It: ASCII Lookup

Type a single letter or digit and see its ASCII decimal code and binary representation.

Enter a character above

The Problem with ASCII 🌍

ASCII was great for English, but what about other languages?

Nepali (नेपाली)

नमस्ते

Japanese (日本語)

こんにちは

Arabic (العربية)

مرحبا

Limitation: With only 128-256 possible values, ASCII cannot represent characters from most of the world's languages.

The Universal Solution: Unicode

Unicode is a modern standard designed to fix ASCII's limitations.

Its goal is to represent every character from every language.
It can represent over 1 million unique characters (including emojis! 👍🎉).
It is the dominant standard for the web, modern operating systems, and software development.

The most common implementation of Unicode is UTF-8, which is backward compatible with ASCII.

ASCII vs. Unicode at a Glance 🔍

ASCII

Scope: English-centric
Size: 7 or 8 bits
Characters: 128-256
Use: Legacy systems

Unicode (UTF-8)

Scope: Universal (All languages)
Size: Variable (1-4 bytes)
Characters: Over 149,000+
Use: Modern standard

Quiz: ASCII or Unicode?

For each situation, choose whether ASCII or Unicode is the right choice.

1. Sending an English-only plain text file in 1985. ASCII Unicode
2. A Nepali government website displaying Devanagari text. ASCII Unicode
3. An app that needs to support Japanese, Arabic, and emoji. ASCII Unicode
4. A legacy system that only uses uppercase English letters A-Z. ASCII Unicode

What About Programs?

Just like data, program instructions must also be in binary for the CPU to execute them.

High-Level Code (Human-readable)

print("Hello, World!")

⬇️

A Compiler or Interpreter translates the code.

⬇️

Machine Code (Binary)

01101000 01100101 01101100 ...

Practical Application in Nepal 🇳🇵

Language and Script: The Nepali language uses the Devanagari script (e.g., क, ख, ग). ASCII cannot represent these characters.
Digital Nepal: Unicode (UTF-8) is essential for all digital services in Nepal, from government websites and the Nagarik App to news portals and social media. It allows us to type and read in Nepali online.
Tech Market: When buying a phone or laptop in Nepal, storage capacity (measured in GB or TB) is a key factor, determining how many photos, videos, and apps you can store.

Key Takeaways ⚡

Computers represent everything using the binary system (0s and 1s) because of their electronic nature (on/off).
A bit is a single 0 or 1. A byte is a group of 8 bits and is the standard unit for measuring storage.
ASCII is an older, limited encoding for English text.
Unicode is the modern, universal standard that supports all world languages, including Nepali.
Program code must be compiled into binary machine code before a computer can run it.

Applications of Computers in Modern Society

Learning Objectives

In this part of today's lecture, you will be able to understand the wide-reaching impact of computers across various sectors of society.

✅ Identify and describe major application areas of computers.
✅ Provide specific examples of computer use in fields like business, education, and healthcare.
✅ Understand the transformative impact of computers on entertainment and communication.

The Digital Backbone of Society

Computers have become an indispensable part of modern life. Their ability to process vast amounts of data quickly and accurately has revolutionized nearly every field of human activity.

⚡ From global commerce to personal communication, computers are the fundamental tool that powers our world.

Business and E-Commerce 📊

Computers are the engine of modern business operations.

Core Operations:

Financial Record Keeping
Inventory Management
Marketing and Sales
Internal & External Communication

E-commerce: Platforms that allow businesses to sell products and services online, reaching a global market.

CRM Systems: (Customer Relationship Management) Software to manage customer data, interactions, and support.

Interactive: Business Applications

Match each business scenario to the correct computer application area:

0 of 4 answered

Education and E-Learning 🎓

The classroom has expanded beyond physical walls, thanks to computer technology.

For Students: Access to e-learning platforms, online research, collaborative project tools, and digital submissions.
For Teachers: Digital lesson planning, creating presentations, tracking student progress, and online grading.

Think: How have computers changed the way you study for this course compared to how you studied in primary school?

Interactive: Student or Teacher Tool?

Student Teacher

Click whether each tool/task is primarily used by a Student or a Teacher:

0 of 5 answered

Healthcare Transformation 🩺

Computers play a critical role in patient care, diagnosis, and medical research.

EHRs

Electronic Health Records provide instant, secure access to patient data for better-coordinated care.

Medical Imaging

Powerful computers process data from MRI and CT scanners to create detailed images of the human body.

Research

Computers are essential for analyzing clinical trial data, drug development, and mapping genomes.

Interactive: Healthcare IT Scenario Quiz

Which computer application in healthcare is being used in each scenario?

0 of 3 answered

Science and Engineering 🔬

Computers are used to solve some of the world's most complex problems.

Performing complex mathematical calculations.
Modeling and simulating complex systems (e.g., weather, aerodynamics).
Analyzing massive datasets from experiments and observations.

Supercomputers: Used for exceptionally demanding tasks like climate modeling, nuclear simulations, and aerospace engineering.

Entertainment Reimagined 🎬🎮

The entertainment industry has been completely reshaped by digital technology.

Visual Media

Movies/TV: Creation of stunning special effects (CGI) and digital editing.
Video Games: An entire industry built on powerful computer graphics and processing.

Audio & Streaming

Music: Digital tools for composing, recording, mixing, and distribution.
Streaming: Services like Netflix & Spotify use vast computer networks to deliver on-demand content.

Interactive: Entertainment Technology — True or False?

Mark each statement True or False about how computers power the entertainment industry:

Statement	Your Answer	Result