🎨

Binary & Online Graphics

How computers represent images using 1s and 0s, and the difference between bitmap and vector graphics

🎯 Learning Objectives

Understand how bitmap images are represented in binary
Explain the features of bitmap and vector image types
Create a binary word to represent a simple bitmap image
Create a bitmap image from a binary word
Perform simple binary addition

1.1 What Are Bitmap Images?

📘 Key Term: Bitmap Image

A bitmap image is made up of a grid of tiny squares called pixels (short for picture elements). Each pixel is assigned a colour, and that colour is stored as a binary number.

Think of a bitmap image like a mosaic — thousands (or millions) of tiny coloured tiles arranged in a grid to form a picture. The more pixels you use, the more detailed (higher resolution) the image becomes.

How Colour Depth Affects Images

The number of bits per pixel determines how many colours are available. This is called the colour depth.

Colour Depth	Bits Per Pixel	Number of Colours	Example
1-bit	1	2 (2¹)	Black and white only
2-bit	2	4 (2²)	Black, dark grey, light grey, white
4-bit	4	16 (2⁴)	Basic colour palette
8-bit	8	256 (2⁸)	GIF images
24-bit	24	16,777,216 (2²⁴)	True colour photographs

1-Bit Images (Black and White)

In a 1-bit image, each pixel uses just 1 bit of data:

0 = White
1 = Black

Example: A Cross Symbol (8×8 pixels, 1-bit colour)

Pixel Grid:

Binary Representation:

                  Row 1: 0 0 1 1 1 1 0 0

                  Row 2: 0 0 1 0 1 0 0 0

                  Row 3: 0 0 1 1 1 1 0 0

                  Row 4: 0 0 0 1 1 0 0 0

                  Row 5: 0 1 1 1 1 1 1 0

                  Row 6: 0 0 0 1 1 0 0 0

                  Row 7: 0 0 0 1 1 0 0 0

                  Row 8: 0 0 1 0 0 1 0 0

Each row of 8 pixels becomes one byte (8 bits) of data.

2-Bit Images (Four Shades)

With 2 bits per pixel, we can represent four different values:

Binary Code	Denary Value	Colour
`00`	0	White
`01`	1	Light Grey
`10`	2	Dark Grey
`11`	3	Black

Example: 2-Bit Image (8×8 pixels)

Notice how 2-bit colour adds grey shades for more detail. Each pixel now needs 2 bits instead of 1.

📝 Activity 1.1 — Binary to Image

Convert this binary data into an 8×8 pixel image on graph paper. Use 1-bit colour (0 = white, 1 = black):

              00011000 00100100 01000010 01111110

              01000010 01000010 01000010 00000000

Challenge: Now create your own 8×8 image and write out its binary representation!

1.2 Vector Graphics

📘 Key Term: Vector Graphic

A vector graphic is made up of mathematical descriptions of shapes — using points (co-ordinates) and lines between them. Instead of storing individual pixels, vector files store instructions like "draw a circle at position (100, 50) with radius 30".

Bitmap vs Vector: The Key Differences

Feature	Bitmap 🖼️	Vector ✏️
Made of	Pixels (tiny coloured squares)	Points, lines and mathematical shapes
When enlarged	Becomes pixelated (blurry/blocky)	Stays sharp (redrawn at new size)
File size	Usually larger (stores every pixel)	Usually smaller (stores co-ordinates only)
Photo-realistic?	Yes — great for photographs	No — better for logos, icons, diagrams
Common formats	JPEG, PNG, GIF, BMP	SVG, AI, EPS
Editing	Edit individual pixels	Edit shapes and objects

What Happens When You Zoom In?

🖼️ Bitmap

Gets pixelated & blurry
Quality is LOST

⟺

✏️ Vector

Stays perfectly sharp
Quality is MAINTAINED

💡 Did You Know?

Company logos are almost always created as vector graphics. This means they can be printed on a tiny business card OR a massive billboard without losing any quality!

1.3 Binary Addition

In Year 7, you learned to convert between binary and denary. Now we'll learn how to add binary numbers together — just like adding denary numbers, but with only 0s and 1s!

The Rules of Binary Addition

Calculation	Result	Explanation
`0 + 0`	`0`	Nothing plus nothing = nothing
`0 + 1`	`1`	Nothing plus one = one
`1 + 0`	`1`	One plus nothing = one
`1 + 1`	`10`	One plus one = two = 0 carry 1
`1 + 1 + 1`	`11`	Three in binary = 1 carry 1

⚠️ The Key Difference

In denary, 1 + 1 = 2. But in binary there is no digit "2"! So 1 + 1 = 10 (which means "write 0, carry 1" — just like 5 + 5 = 10 in denary).

Worked Example: Add 00110101 + 00011010

Step-by-step binary addition

               Carry: 
                0 1 1 1 1 0 0 0

               0 0 1 1 0 1 0 1

               + 0 0 0 1 1 0 1 0

               ─────────────────

               = 0 1 0 0 1 1 1 1

Verification: 53 + 26 = 79 ✓ (00110101 = 53, 00011010 = 26, 01001111 = 79)

Start from the rightmost column (just like denary addition)

Column 1 (units): 1 + 0 = 1

Column 2: 0 + 1 = 1

Column 3: 1 + 0 = 1

Column 4: 1 + 1 = 10 → write 0, carry 1

Column 5: 1 + 0 + 1 (carry) = 10 → write 0, carry 1

Column 6: 0 + 1 + 1 (carry) = 10 → write 0, carry 1

Column 7: 0 + 0 + 1 (carry) = 1

📝 Activity 1.2 — Binary Addition Practice

Calculate the following binary additions. Check your answers by converting to denary first.

00001111 + 00000001
01010101 + 00101010
00110011 + 00001100
01100100 + 00011001

📋 Chapter 1 Summary

Bitmap images are made of pixels; each pixel's colour is stored as binary
1-bit colour = 2 colours; 2-bit = 4 colours; more bits = more colours
Vector graphics use mathematical descriptions of shapes (points and lines)
Bitmaps pixelate when enlarged; vectors stay sharp
Bitmaps are better for photos; vectors are better for logos and diagrams
Binary addition follows the same column method as denary, but 1 + 1 = 10 (carry 1)

✅ Check Your Understanding

1. What is a pixel?

2. How many colours can be represented with 2-bit colour depth?

3. What happens to a bitmap image when you enlarge it? Why?

4. Give two advantages of vector graphics over bitmap graphics.

5. Calculate: 01010110 + 00101001

02

💾

Data on the Web

Understanding storage capacity, file sizes and how images are compressed for the web

🎯 Learning Objectives

Understand and use terms describing storage capacity
Convert between storage units
Calculate storage requirements for files
Understand image compression and Run Length Encoding (RLE)

2.1 Units of Storage

All data in a computer is stored as bits (binary digits). But files are usually much larger than a single bit, so we use larger units to measure storage.

📘 Key Terms: Storage Units

The International Electrotechnical Commission (IEC) defines storage using base-2 (binary) units:

Unit	Symbol	Size	Equivalent
Bit	b	Smallest unit	A single 0 or 1
Byte	B	8 bits	Can store one character (e.g., the letter 'A')
Kibibyte	KiB	2¹⁰ bytes	1,024 bytes
Mebibyte	MiB	2²⁰ bytes	1,048,576 bytes (1,024 KiB)
Gibibyte	GiB	2³⁰ bytes	1,073,741,824 bytes (1,024 MiB)

The Storage Ladder

GiB (Gibibyte)
1,024 MiB

↑ ×1,024

MiB (Mebibyte)
1,024 KiB

↑ ×1,024

KiB (Kibibyte)
1,024 bytes

↑ ×1,024

Byte
8 bits

↑ ×8

Bit
0 or 1

💡 Why 1,024 and not 1,000?

Storage units use base-2 (binary) so each level is 2¹⁰ = 1,024 times bigger, not 1,000. Data transfer speeds (Mbps, Gbps) use base-10 (1,000). This difference can cause confusion!

2.2 Calculating Storage Requirements

You need to be able to work out how much storage space files will use. Here's the formula for images:

📘 Image File Size Formula

File size (bits) = Width (pixels) × Height (pixels) × Colour depth (bits per pixel)

To convert to bytes, divide by 8.

Worked Example

Calculate the file size of a 1920 × 1080 image with 24-bit colour

Step 1: Total pixels = 1,920 × 1,080 = 2,073,600 pixels

Step 2: Total bits = 2,073,600 × 24 = 49,766,400 bits

Step 3: Total bytes = 49,766,400 ÷ 8 = 6,220,800 bytes

Step 4: Convert to KiB = 6,220,800 ÷ 1,024 = 6,075 KiB

Step 5: Convert to MiB = 6,075 ÷ 1,024 ≈ 5.93 MiB

📝 Activity 2.1 — Storage Calculations

An image is 640 × 480 pixels with 8-bit colour. What is its file size in KiB?
You have a 2 GiB USB stick. How many 5 MiB photos can you store on it?
A 1-bit image is 100 × 100 pixels. What is its file size in bytes?
A music file is 4 MiB. How many of these can fit on a 32 GiB memory card?

2.3 Image Compression

Image files can be very large — especially high-resolution photos. To share images on the web, we often need to make them smaller. This process is called compression.

📘 Key Term: Compression

Compression reduces the file size of data so it takes up less storage space and can be transmitted more quickly over the Internet.

Run Length Encoding (RLE)

📘 Key Term: Run Length Encoding

Run Length Encoding (RLE) is a lossless compression method. Instead of storing every pixel individually, it stores the colour and how many consecutive pixels are that colour.

Lossless means no data is lost — the original image can be perfectly reconstructed.

How RLE Works

Before Compression (original data):

W

B

W

B

16 values stored = 16 units of data

⬇️

After RLE Compression:

W5

B3

W7

B1

Only 8 values stored (4 pairs) = 50% compression!

RLE works best on images with large areas of the same colour (like simple logos or icons). It's less effective on photographs with many different colours.

📝 Activity 2.2 — RLE Compression

Compress this row of pixel data using RLE:

              B B B B W W W W W W B B B W W W W W B B
            

Now decompress this RLE data back into individual pixels:

              W3, B6, W2, B1, W4
            

📋 Chapter 2 Summary

Storage is measured in bits, bytes, KiB, MiB and GiB (base-2 units)
Each unit is 1,024 times the previous one (except bits to bytes = ×8)
Image file size = width × height × colour depth (in bits)
Compression reduces file sizes for faster transmission
RLE is a lossless compression method that records colour + count
RLE works best for images with large areas of the same colour

✅ Check Your Understanding

1. How many bytes are in 1 KiB?

2. How many KiB are in 1 MiB?

3. Calculate the file size in bytes of a 200 × 200 pixel image with 1-bit colour.

4. What does RLE stand for? Is it lossy or lossless?

5. Use RLE to compress: W W W B B B B B W W

03

📊

Processing Data

Mastering spreadsheets with formatting, formulae, functions and real-world modelling

🎯 Learning Objectives

Format a worksheet effectively
Use formulae with multiple arithmetic operators and percentages
Use spreadsheet functions: SUM, AVERAGE, MAX, MIN, COUNT, LEN
Work with multiple worksheets and cross-sheet referencing
Understand the environmental impact of technology

3.1 Formatting a Worksheet

A well-formatted spreadsheet is easier to read, understand and use. Here are the key formatting skills you need:

Formatting Feature	What It Does	How to Use It
Number Format	Displays numbers as currency (£), percentage (%), date, etc.	Select cells → Format Cells → Number tab
Decimal Places	Controls how many decimal places are shown	Increase/Decrease Decimal buttons
Row Height / Column Width	Adjusts the size of rows and columns	Drag borders or right-click → Row Height
Merge Cells	Combines multiple cells into one large cell	Select cells → Merge & Centre
Cell Borders	Adds visible borders around cells	Home → Borders dropdown
Cell Shading	Adds background colour to cells	Home → Fill Colour
Hide Rows/Columns	Hides data from view without deleting it	Right-click row/column → Hide

3.2 Formulae and Operators

A formula is a calculation that you type into a cell. All formulae start with an equals sign (=).

Arithmetic Operators in Spreadsheets

Operator	Meaning	Example Formula	If A1=10, B1=3
`+`	Addition	`=A1+B1`	13
`-`	Subtraction	`=A1-B1`	7
`*`	Multiplication	`=A1*B1`	30
`/`	Division	`=A1/B1`	3.33

Calculating Percentages

To calculate a percentage in a spreadsheet:

            To find 20% of a value in cell A1: =A1*20/100 or =A1*0.2 To add VAT
            (20%) to a price in A1: =A1*1.2 To find what percentage B1 is of A1:
            =B1/A1*100
          

3.3 Spreadsheet Functions

Functions are pre-built formulae that perform common calculations automatically:

Function	What It Does	Example	If A1:A5 = 10,20,30,40,50
`=SUM()`	Adds up all values	`=SUM(A1:A5)`	150
`=AVERAGE()`	Calculates the mean	`=AVERAGE(A1:A5)`	30
`=MAX()`	Finds the highest value	`=MAX(A1:A5)`	50
`=MIN()`	Finds the lowest value	`=MIN(A1:A5)`	10
`=COUNT()`	Counts cells with numbers	`=COUNT(A1:A5)`	5
`=LEN()`	Counts characters in text	`=LEN("Hello")`	5

Example Spreadsheet

	A	B	C	D
1	Product	Price	Quantity	Total
2	Widget A	£5.50	10	=B2*C2
3	Widget B	£3.25	25	=B3*C3
4	Widget C	£8.00	5	=B4*C4
5	Grand Total			=SUM(D2:D4)

3.4 Subprograms as Abstractions

📘 Key Term: Abstraction

An abstraction is a simplified model of something more complex. Spreadsheet functions like SUM and AVERAGE are abstractions — they hide the complex calculations and give you a simple tool to use. Similarly, you can create spreadsheet models that simulate real-world scenarios (like a sandwich shop calculator or a speed camera system).

3.5 Multiple Worksheets

A spreadsheet file (called a workbook) can contain multiple worksheets (tabs). You can reference data from one sheet in another using cross-sheet referencing:

            Reference cell A1 on a sheet called "Sales": =Sales!A1 Sum cells A1
            to A10 from the "January" sheet: =SUM(January!A1:A10)
          

3.6 Environmental Impact of Technology

Technology has a significant impact on our environment. As responsible digital citizens, we should understand these effects:

🏭 Manufacture

Making devices requires mining rare earth metals, using energy-intensive factories and producing toxic waste. Often done in developing countries.

⚡ Use

Devices consume electricity. Data centres (which power the cloud and Internet) use enormous amounts of energy and water for cooling.

🗑️ Disposal

E-waste is a growing problem. Many devices end up in landfill, leaking toxic chemicals. Only a fraction of electronic waste is properly recycled.

♻️ Solutions

Recycling schemes, using devices longer, buying refurbished, donating old tech, and supporting companies that use renewable energy.

📝 Activity 3.1 — Environmental Impact Spreadsheet

Create a spreadsheet with multiple worksheets that tracks the environmental impact of technology:

Sheet 1: Number of devices manufactured per year (by country)
Sheet 2: Energy consumed during use (kWh per device per year)
Sheet 3: Summary using cross-sheet references, with SUM, AVERAGE and percentage calculations

Format your spreadsheet with appropriate currency, number formats, borders and shading.

📋 Chapter 3 Summary

Formatting makes spreadsheets easier to read (currency, percentages, borders, shading)
Formulae use =, +, -, *, / and cell references
Key functions: SUM, AVERAGE, MAX, MIN, COUNT, LEN
Functions are abstractions that hide complex calculations
Multiple worksheets can be linked using cross-sheet referencing (=SheetName!Cell)
Technology impacts the environment through manufacture, energy use and disposal

✅ Check Your Understanding

1. What symbol must every formula start with?

2. Write a formula to calculate 15% of the value in cell B3.

3. What is the difference between SUM and COUNT?

4. How would you reference cell C5 on a worksheet called "Data"?

5. Name two environmental problems caused by technology disposal.

04

📈

Analysing Data

Sorting, filtering and visualising data to discover patterns and present findings

🎯 Learning Objectives

Sort data in ascending and descending order on single and multiple columns
Filter data using one or more criteria
Create appropriate graphs and charts
Select and justify the right chart type for different data
Format charts with titles, axis labels and legends

4.1 Sorting Data

📘 Key Term: Sorting

Sorting means arranging data in a specific order. Ascending order goes from smallest to largest (A→Z, 1→100). Descending order goes from largest to smallest (Z→A, 100→1).

Types of Sorting

📊 Single Column Sort

Sort all data based on one column. For example, sort a class list alphabetically by surname.

📊 Multi-Column Sort

Sort by one column first, then by another within that. For example, sort by class first, then by surname within each class.

⚠️ Important

Always select all your data (including related columns) before sorting! If you only sort one column, the data in other columns won't move with it, and your information will become mixed up.

4.2 Filtering Data

📘 Key Term: Filtering

Filtering means showing only the data that meets certain criteria (conditions) while temporarily hiding the rest. The hidden data is NOT deleted — it's just hidden from view.

Examples of filtering:

Show only students who scored above 70%
Show only products that cost less than £10
Show only orders from "January" AND with a total over £50

You can apply filters on one column or multiple columns at the same time to narrow down your data further.

4.3 Charts and Graphs

Visualising data in charts and graphs makes patterns and trends much easier to spot. But choosing the right type of chart is crucial!

Chart Type	Best For	Example Use
Bar / Column Chart	Comparing categories	Comparing sales of different products; survey results
Pie Chart	Showing proportions of a whole	Market share; favourite subjects in a class
Line Chart	Showing trends over time	Temperature over a week; website visitors per month
Scatter Graph	Showing relationships between two variables	Height vs weight; study hours vs test score

Formatting Charts Effectively

Every chart should include:

A descriptive title — tells the reader what the chart shows

Axis labels — what each axis represents (with units)

A legend (key) — explains what each colour/pattern represents

Appropriate scale — axes should start at zero where relevant

Clear colours — easy to distinguish and suitable for printing

Justifying Your Choice

When selecting a chart type, you should be able to explain why you chose it:

✅ Good Justification

"I used a line chart because I wanted to show how temperature changed over time, and line charts are best for showing trends."

❌ Poor Justification

"I used a line chart because it looks nice."

📝 Activity 4.1 — Data Analysis Project

You have been given a dataset of weather data for 12 months. Complete the following tasks:

Sort the data by temperature (highest to lowest)
Filter to show only months with rainfall above 50mm
Create a line chart showing temperature over the 12 months
Create a bar chart comparing rainfall for each month
Create a scatter graph showing the relationship between temperature and sunshine hours
Justify why you chose each chart type

Format each chart with a title, axis labels and legend.

📋 Chapter 4 Summary

Sorting arranges data in ascending (A→Z) or descending (Z→A) order
Multi-column sorting sorts by primary criteria first, then secondary
Filtering shows only data that meets specified criteria
Bar charts compare categories; pie charts show proportions
Line charts show trends over time; scatter graphs show relationships
All charts need titles, axis labels and legends
You should justify your choice of chart type

✅ Check Your Understanding

1. What is the difference between ascending and descending sort?

2. When you filter data, is the hidden data deleted?

3. Which chart type would be best for showing how profits changed over 5 years? Why?

4. Which chart type would be best for showing the percentage of students who prefer each subject?

5. Name three things every chart should include.

05

📱

Programming (C)

Lists, subprograms, logic operators and building real applications

🎯 Learning Objectives

Use variables with appropriate type declarations
Use sequence, selection and iteration (building on Year 7)
Understand and use lists (arrays): indices, append, insert, sort, slicing
Define and use subprograms (procedures and functions)
Use logic operators: AND, OR, NOT
Locate and fix both syntax errors and logic errors

5.1 Lists (One-Dimensional Arrays)

📘 Key Term: List

A list (also called a one-dimensional array) is a variable that can hold multiple values in a specific order. Each value has a position number called an index, starting from 0.

            # Creating a list
            fruits = ["apple", "banana",
            "cherry",
            "date"]

            # Accessing items by index (remember: starts at 0!)
            print(fruits[0])
            # Output: apple
            print(fruits[2])
            # Output: cherry
            print(fruits[-1])
            # Output: date (last item)
          

List Methods

Method	What It Does	Example
`.append(item)`	Adds an item to the end of the list	`fruits.append("elderberry")`
`.insert(index, item)`	Adds an item at a specific position	`fruits.insert(1, "blueberry")`
`.sort()`	Sorts the list in ascending order	`fruits.sort()`
`.remove(item)`	Removes the first occurrence of an item	`fruits.remove("banana")`
`len(list)`	Returns the number of items	`len(fruits)` → 4

            scores = [85, 92, 78,
            95, 88]

            # Replacing an item
            scores[2]
            =
            80
            # Changes 78 to 80

            # Adding items
            scores.append(91)
            # Adds 91 to the end

            # Slicing a list
            print(scores[1:4])
            # Output: [92, 80, 95]

            # Traversing (looping through) a list
            for score
            in
            scores:
            print(score)
          

5.2 Subprograms

📘 Key Term: Subprogram

A subprogram is a named block of code that performs a specific task. It can be called (used) whenever needed, avoiding repetition. In Python, subprograms are created using the def keyword.

Procedure — a subprogram that performs an action but does NOT return a value
Function — a subprogram that performs an action AND returns a value

            # A procedure (does something, returns nothing)
            def
            greet(name): print("Hello, "
            + name +
            "!")

            greet("Alice") # Output: Hello, Alice!
            greet("Bob")
            # Output: Hello, Bob!

            # A function (calculates and returns a value)
            def
            calculate_area(width, height):
            area =
            width *
            height
            return
            area

            result =
            calculate_area(5, 3)
            print(result) # Output: 15
          

5.3 Logic Operators

Logic operators let you combine multiple conditions in selection and iteration:

Operator	Meaning	Example	Result
`and`	BOTH conditions must be True	`age >= 13 and age <= 19`	True only for teenagers
`or`	AT LEAST ONE must be True	`day == "Saturday" or day == "Sunday"`	True on weekends
`not`	Reverses True to False and vice versa	`not raining`	True when it's NOT raining

            temperature =
            25
            raining =
            False

            if
            temperature >
            20 and
            not
            raining:
            print("Perfect day for a picnic!") elif
            temperature >
            20 or
            not
            raining:
            print("Might be okay outside.") else:
            print("Stay inside!")
          

5.4 Syntax Errors vs Logic Errors

🔤 Syntax Error

A mistake in the grammar of the code. The program won't run at all.

Missing colon after if
Misspelled keyword
Missing brackets
Incorrect indentation

The computer tells you about these!

🧠 Logic Error

The code runs without crashing, but gives the wrong result.

Using + instead of *
Wrong comparison operator
Loop runs too many/few times
Conditions in wrong order

The computer can't detect these — YOU must find them!

            # SYNTAX ERROR — program won't run
            if
            score >
            50
            # Missing colon!
            print("Pass")

            # LOGIC ERROR — program runs but gives wrong answer
            def
            calculate_average(a, b,
            c):
            return
            a + b +
            c /
            3
            # Bug! Should be (a + b + c) / 3
            # Without brackets, only c is divided by 3
          

📝 Activity 5.1 — Quiz Program with Lists

Create a quiz program that:

Stores 5 questions in a list
Stores 5 correct answers in another list
Uses a for loop to ask each question
Uses a subprogram called check_answer() to check if the answer is correct
Uses a variable to track the score
Displays the final score and a message using if/elif/else

Extension: Add logic operators so the program also says "Well done!" if the score is above 3 AND the user answered the last question correctly.

📋 Chapter 5 Summary

Lists store multiple values in order, accessed by index (starting at 0)
List methods: append(), insert(), sort(), remove()
Traverse lists using for loops
Subprograms: procedures (no return) and functions (return a value)
Logic operators: AND (both true), OR (at least one true), NOT (reverses)
Syntax errors stop the program running; logic errors give wrong results

✅ Check Your Understanding

1. If colours = ["red", "green", "blue"], what is colours[1]?

2. What does .append() do?

3. What is the difference between a procedure and a function?

4. If x = 5, what does x > 3 and x < 10 evaluate to?

5. Explain the difference between a syntax error and a logic error.

06

🔐

Software & Communication

Operating systems, the World Wide Web, wireless technologies, cyber security and digital surveillance

🎯 Learning Objectives

Know that operating systems provide the interface between machine and user
Understand the purpose of systems/utility software
Understand the components of the World Wide Web
Understand hardware components used to access the Internet
Select appropriate wireless communication methods (Wi-Fi, Bluetooth, NFC)
Understand cyber security vulnerabilities and digital surveillance

6.1 Types of Software

All software falls into one of three categories:

The Software Hierarchy

👤 Human Users

↕

📱 Application Software

↕

⚙️ Operating System

+ Utility Software

↕

🖥️ Hardware

Operating System (OS)

📘 Key Term: Operating System

The operating system is the most important software on a computer. It provides the interface between the hardware and the user, managing files, memory, processes and connected devices.

Examples: Windows, macOS, Linux, Android, iOS, ChromeOS

Application Software

📘 Key Term: Application Software

Application software (apps) allows users to carry out specific tasks. The OS must be running before applications can be used.

📝 Office Productivity

Word processors, spreadsheets, presentation software, databases

🌐 Web Authoring

Software for creating websites (e.g., Dreamweaver, WordPress)

🎨 Image & Sound Editing

Photoshop, GIMP, Audacity, GarageBand

📧 Communication

Email clients, messaging apps, video conferencing

Utility Software

📘 Key Term: Utility Software

Utility software helps manage, maintain and protect the computer system. It runs in the background to keep your computer working smoothly.

Utility	Purpose
Anti-malware / Anti-virus	Detects and removes malicious software (viruses, trojans, worms)
Anti-spyware	Prevents software from secretly monitoring your activity
File compression	Makes files smaller for storage or sharing (ZIP)
Backup software	Creates copies of files in case of data loss
Disk defragmenter	Reorganises fragmented files on a hard drive for faster access
File manager	Organises, moves, copies and deletes files and folders

6.2 Components of the World Wide Web

In Year 7, you learned the difference between the Internet and the WWW. Now let's look at the components that make the Web work:

Component	What It Is
Web Server	A powerful computer that stores websites and sends web pages to your browser when requested
URL	Uniform Resource Locator — the address of a web page (e.g., `https://www.example.com/page`)
ISP	Internet Service Provider — the company that provides your Internet connection (e.g., BT, Sky, Virgin)
HTTP	HyperText Transfer Protocol — the rules for transferring web pages between server and browser
HTTPS	The secure version of HTTP — data is encrypted for safety 🔒
HTML	HyperText Markup Language — the code used to create the structure and content of web pages

6.3 Hardware for Internet Access

Several hardware components work together to connect your device to the Internet:

📡 Wireless Access Point (WAP)

Broadcasts a Wi-Fi signal so wireless devices can connect to the network.

🔌 Switch

Connects multiple devices on a local network and directs data to the correct device.

🌐 Router

Directs data between your local network and the wider Internet. Decides the best route for data packets.

📞 Modem

Modulator/Demodulator — converts digital signals from your computer into signals that can travel over telephone/cable lines, and vice versa.

💡 Did You Know?

Your home "router" (the box from your ISP) actually contains all four components — a modem, router, switch AND wireless access point — combined into one device!

6.4 Wireless Communication Methods

There are three main types of wireless communication. Each has different strengths:

Technology	Range	Speed	Best For
Wi-Fi 📶	Up to ~100m indoors	Very fast	Internet access, streaming, downloading
Bluetooth 🔵	Up to ~10m	Moderate	Headphones, keyboards, file sharing between nearby devices
NFC 📱	Up to ~4cm	Slow	Contactless payments, travel cards, quick device pairing

📘 Key Term: NFC

Near Field Communication (NFC) is a very short-range wireless technology. Because it only works within centimetres, it's very secure — perfect for contactless payments with your bank card or phone.

6.5 Cyber Security Vulnerabilities

Data stored on computers and transmitted over networks is vulnerable to attack. Here are some common technical weaknesses:

🔓 Unpatched Software

Software that hasn't been updated may contain known security holes that hackers can exploit. Always install updates!

💾 Portable Storage Devices

USB drives can carry malware from one computer to another. They can also be lost or stolen, exposing sensitive data.

👂 Eavesdropping

Attackers can intercept data as it travels over unsecured networks (especially public Wi-Fi). This is why HTTPS is important!

🎣 Social Engineering

Tricking people into revealing passwords or sensitive information through phishing emails, fake websites or phone calls.

6.6 Digital Surveillance

Technology allows organisations and governments to monitor people's movements and communications. This raises important questions about privacy vs security.

Method	How It Works	Debate
CCTV	Cameras record video in public places and buildings	Helps catch criminals but reduces privacy
ID Cards	Identification cards track when and where they are scanned	Useful for security but tracks movements
GPS Data	Mobile phones and sat-navs record location data	Helpful for navigation but can be used to track individuals
Eavesdropping	Monitoring phone calls, emails or Internet activity	Can prevent terrorism but violates privacy

⚠️ Think About It

The debate around surveillance often comes down to: "Does increased security justify reduced privacy?" There is no easy answer — different people, organisations and governments have very different views on this.

📝 Activity 6.1 — Software Classification

Sort these examples into the correct category: Application Software, Operating System, or Utility Software.

Microsoft Word
Windows 11
Norton Antivirus
Google Chrome
WinZip
Android
Photoshop
Windows Defender

📝 Activity 6.2 — WWW Diagram

Create a labelled diagram showing how a user accesses a website. Include:

User's device with web browser
Home router (with WAP, switch, router, modem labelled)
ISP
Web server
URL, HTTP/HTTPS and HTML labels

Use arrows to show the direction of data flow.

📝 Activity 6.3 — Wireless Technology Scenarios

For each scenario, choose the best wireless technology (Wi-Fi, Bluetooth or NFC) and justify your choice:

Paying for your lunch in the school canteen
Listening to music on wireless headphones
Streaming a movie at home
Sharing a photo with a friend standing next to you
Connecting a wireless keyboard to your tablet

📋 Chapter 6 Summary

Software types: Application (user tasks), Operating System (manages hardware), Utility (maintenance & protection)
The OS provides the interface between hardware and user
WWW components: web server, URL, ISP, HTTP/HTTPS, HTML
Internet hardware: WAP, switch, router, modem (often combined in home "routers")
Wireless methods: Wi-Fi (long range, fast), Bluetooth (short range), NFC (very short range)
Cyber vulnerabilities: unpatched software, USB drives, eavesdropping
Surveillance technologies raise privacy vs security debates

✅ Check Your Understanding

1. What is the main purpose of an operating system?

2. Give two examples of utility software and explain what they do.

3. What does HTTPS stand for and how is it different from HTTP?

4. Name the four hardware components in a typical home "router".

5. Why is NFC suitable for contactless payments?

6. Give one argument FOR and one argument AGAINST the use of CCTV in public places.

📚

Glossary

Key terms and definitions from all Year 8 chapters

Term	Definition
Abstraction	A simplified model that hides unnecessary complexity
AND (logic)	Logic operator — both conditions must be True for the result to be True
Anti-malware	Utility software that detects and removes malicious software
Application Software	Software that allows users to carry out specific tasks (e.g., word processor)
Ascending Order	Sorting from smallest to largest (A→Z, 0→9)
Binary Addition	Adding binary numbers using column addition with carries (1+1=10)
Bitmap Image	An image made up of a grid of pixels, each with a binary colour value
Bluetooth	Short-range wireless technology (~10m) for connecting devices
Colour Depth	The number of bits used to represent each pixel's colour
Compression	Reducing file size for easier storage and faster transmission
Cross-sheet Referencing	Using data from one worksheet in a formula on another worksheet
Cyber Attack	An attempt to damage, disrupt or gain unauthorised access to a computer system
Descending Order	Sorting from largest to smallest (Z→A, 9→0)
Eavesdropping	Intercepting data as it travels over a network
E-waste	Electronic waste — discarded electrical devices
Filtering	Showing only data that meets specific criteria
Formula	A calculation in a spreadsheet cell, starting with =
Function (spreadsheet)	A pre-built formula (e.g., SUM, AVERAGE, MAX, MIN)
Function (programming)	A subprogram that performs a task and returns a value
Gibibyte (GiB)	Storage unit = 1,024 MiB = 1,073,741,824 bytes
HTML	HyperText Markup Language — code used to create web pages
HTTP / HTTPS	Protocol for transferring web pages; HTTPS is the encrypted (secure) version
ISP	Internet Service Provider — company providing Internet access
Kibibyte (KiB)	Storage unit = 1,024 bytes
List (Array)	A data structure that holds multiple values in order, accessed by index
Logic Error	An error where the program runs but produces incorrect results
Lossless Compression	Compression where no data is lost — original can be perfectly restored
Mebibyte (MiB)	Storage unit = 1,024 KiB = 1,048,576 bytes
Modem	Converts digital signals to analogue and vice versa for transmission
NFC	Near Field Communication — very short range wireless (~4cm)
NOT (logic)	Logic operator — reverses True to False and False to True
Operating System	Software that manages hardware and provides the user interface
OR (logic)	Logic operator — at least one condition must be True
Pixel	The smallest element of a bitmap image (picture element)
Procedure	A subprogram that performs a task but does not return a value
Router	Directs data packets between networks
RLE	Run Length Encoding — lossless compression recording colour + count
Sorting	Arranging data in ascending or descending order
Subprogram	A named, reusable block of code (procedure or function)
Switch	Connects devices on a local network and directs data to the correct device
Syntax Error	An error in the grammar/structure of code — program won't run
URL	Uniform Resource Locator — the address of a web page
Utility Software	Software that maintains and protects the computer system
Vector Graphic	An image made of mathematical shapes (points and lines), scalable without quality loss
WAP	Wireless Access Point — broadcasts Wi-Fi signal
Web Server	A computer that stores websites and sends pages to browsers

End of Year 8 Textbook

Computing

Computing

📖 Table of Contents

Binary & Online Graphics

🎯 Learning Objectives

1.1 What Are Bitmap Images?

📘 Key Term: Bitmap Image

How Colour Depth Affects Images

1-Bit Images (Black and White)

Example: A Cross Symbol (8×8 pixels, 1-bit colour)

2-Bit Images (Four Shades)

Example: 2-Bit Image (8×8 pixels)

📝 Activity 1.1 — Binary to Image

1.2 Vector Graphics

📘 Key Term: Vector Graphic

Bitmap vs Vector: The Key Differences

What Happens When You Zoom In?

💡 Did You Know?

1.3 Binary Addition

The Rules of Binary Addition

⚠️ The Key Difference

Worked Example: Add 00110101 + 00011010

Step-by-step binary addition

📝 Activity 1.2 — Binary Addition Practice

📋 Chapter 1 Summary

✅ Check Your Understanding

Data on the Web

🎯 Learning Objectives

2.1 Units of Storage

📘 Key Terms: Storage Units

The Storage Ladder

💡 Why 1,024 and not 1,000?

2.2 Calculating Storage Requirements

📘 Image File Size Formula

Worked Example

Calculate the file size of a 1920 × 1080 image with 24-bit colour

📝 Activity 2.1 — Storage Calculations

2.3 Image Compression

📘 Key Term: Compression

Run Length Encoding (RLE)

📘 Key Term: Run Length Encoding

How RLE Works

Before Compression (original data):

After RLE Compression:

📝 Activity 2.2 — RLE Compression

📋 Chapter 2 Summary

✅ Check Your Understanding

Processing Data

🎯 Learning Objectives

3.1 Formatting a Worksheet

3.2 Formulae and Operators

Arithmetic Operators in Spreadsheets

Calculating Percentages

3.3 Spreadsheet Functions

Example Spreadsheet

3.4 Subprograms as Abstractions

📘 Key Term: Abstraction

3.5 Multiple Worksheets

3.6 Environmental Impact of Technology

🏭 Manufacture

⚡ Use

🗑️ Disposal

♻️ Solutions

📝 Activity 3.1 — Environmental Impact Spreadsheet

📋 Chapter 3 Summary

✅ Check Your Understanding

Analysing Data

🎯 Learning Objectives

4.1 Sorting Data

📘 Key Term: Sorting

Types of Sorting

📊 Single Column Sort

📊 Multi-Column Sort

⚠️ Important

4.2 Filtering Data

📘 Key Term: Filtering

4.3 Charts and Graphs

Formatting Charts Effectively

Justifying Your Choice

✅ Good Justification

❌ Poor Justification