1.1.1 What is Hardware? ICDL 1.1.1
Hardware is the physical parts of a computer — anything you can see and touch. This includes the main computer types and all connected equipment.
Main types of computers:
1.1.2 Integrated & External Equipment ICDL 1.1.2
Equipment can be integrated (built into the device) or external (connected separately):
1.1.3 Common Ports & Connectors ICDL 1.1.3
Ports are sockets on a computer where you plug in equipment. Learn these three important ones:
| Port | Full Name | What It Connects | Look |
|---|---|---|---|
| USB | Universal Serial Bus | Almost everything! Mouse, keyboard, phone, printer, flash drives, webcam | Rectangular (USB-A), Oval (USB-C) |
| HDMI | High-Definition Multimedia Interface | Monitors, TVs, projectors — carries both video AND audio | Trapezoidal (wider on top) |
| VGA | Video Graphics Array | Older monitors and projectors — video only (no audio) | Blue, 15-pin D-shape connector |
1.1.4 Starting & Stopping Your Computer ICDL 1.1.4
| Action | What It Does | When to Use |
|---|---|---|
| 🔓 Log In | Enter your username and password to access your account | When you start the computer or switch users |
| 🔒 Log Off / Sign Out | Closes your session but keeps the computer running | When sharing a computer with others |
| 🔁 Restart / Reboot | Turns the computer off and back on again | After installing updates, or when something isn't working |
| ⏹️ Shut Down | Turns the computer completely off | When you're done using it for the day |
| 😴 Sleep / Suspend | Low-power mode; wakes up quickly | When taking a short break |
| 🔄 Switch User | Log in to a different account without closing yours | When someone else needs the computer briefly |
1.1.5–1.1.6 Connecting & Disconnecting Devices ICDL 1.1.5–1.1.6
To connect: Plug the USB cable or device into a USB port. The computer will automatically detect it (this is called "plug and play"). A notification will appear.
To disconnect safely:
- Close all files you're using from the USB device
- Click the "Safely Remove" icon in the system tray (bottom-right corner)
- Select the device and click "Eject"
- Wait for the "Safe to remove" message
- Now unplug the device
Bluetooth is a wireless technology for connecting devices over short distances (up to ~10 meters). Used for wireless keyboards, mice, headphones, and speakers.
To connect (pair):
- Turn on Bluetooth on your computer (Settings → Bluetooth → On)
- Put the device in "pairing mode" (usually hold a button until a light flashes)
- Your computer will discover the device — click on it to pair
- Enter a PIN code if asked (often 0000 or 1234)
- The device is now connected!
To disconnect: Go to Bluetooth settings → click the device → choose "Disconnect" or "Remove".
1.2.1 What is Software? ICDL 1.2.1
Software is a set of instructions (code) that tells hardware what to do. Unlike hardware, you cannot touch software — it lives inside the computer.
🖥️ Operating System (OS): The "boss" software that manages everything — hardware, files, memory, security. Examples: Linux, Windows, macOS, Android, iOS.
📱 Applications (Apps): Programs you use for specific tasks — writing, drawing, browsing. Examples: LibreOffice Writer, Firefox, GIMP.
Software can be installed locally (saved on your computer) or accessed online (used through a web browser, like Google Docs or Nextcloud).
1.2.2 Common Operating Systems ICDL 1.2.2
| OS | Maker | Used On | Open Source? |
|---|---|---|---|
| 🐧 Linux (Ubuntu, Mint, Fedora) | Community | PCs, servers, Raspberry Pi, supercomputers | ✅ Yes — FREE |
| 🪟 Windows | Microsoft | Most PCs & laptops | ❌ No |
| 🍎 macOS | Apple | Mac computers only | ❌ No |
| 📱 Android | Google (based on Linux!) | Most smartphones & tablets | ✅ Partially |
| 🍏 iOS / iPadOS | Apple | iPhone & iPad only | ❌ No |
| 🦊 ChromeOS | Google (based on Linux!) | Chromebooks | ✅ Partially |
1.2.3 Common Applications ICDL 1.2.3
| Category | Purpose | 🔓 Open-Source Example | 🔒 Proprietary Example |
|---|---|---|---|
| 📝 Office Productivity | Documents, spreadsheets, presentations | LibreOffice | Microsoft Office |
| 🌐 Web Browser | Browse the internet | Firefox, Chromium | Google Chrome, Safari |
| 📧 Communications | Email, messaging, video calls | Thunderbird, Element | Outlook, Teams |
| 👥 Social Networking | Connect with others online | Mastodon, Diaspora | Facebook, Instagram |
| 🎨 Design & Media | Photo editing, drawing, video | GIMP, Inkscape, Kdenlive | Photoshop, Premiere |
🎮 Activity: Input or Output? Match the Devices!
Drag each device to the correct category:
2.1.1 The File Manager & Desktop ICDL 2.1.1
The File Manager (called "Files" or "Nautilus" in Linux) is the program used to browse, find, and organise your files and folders. It's like a digital filing cabinet.
The Desktop is the main screen you see after logging in. You can place shortcuts here. The Taskbar/Panel (usually at the top or bottom) shows running apps, the clock, notifications, and system controls.
2.1.2 Common Icons & File Types ICDL 2.1.2
You'll see these icons on your computer. Learn to recognise them:
Common file types you must know:
| Extension | Type | Opens With | Icon |
|---|---|---|---|
.odt / .docx | Word processing document | LibreOffice Writer | 📝 |
.ods / .xlsx | Spreadsheet | LibreOffice Calc | 📊 |
.odp / .pptx | Presentation | LibreOffice Impress | 📽️ |
.pdf | Portable Document Format | PDF Viewer (Evince) | 📄 |
.jpg / .png / .gif | Image file | Image Viewer | 🖼️ |
.mp3 / .wav | Audio file | Music Player | 🎵 |
.mp4 / .avi | Video file | Video Player | 🎬 |
.zip / .tar.gz | Compressed archive | Archive Manager | 📦 |
.exe (Windows) / .AppImage (Linux) | Executable / application | Operating System | ⚙️ |
2.1.3 Folder Hierarchy & Navigation ICDL 2.1.3
Files are organized in a hierarchical structure — folders inside folders, like boxes inside bigger boxes. In Linux:
2.1.4 Changing View Modes ICDL 2.1.4
The File Manager can display files in different views:
| View | Shows | Best For |
|---|---|---|
| 🔲 Icons / Tiles | Large icons with file names | Quickly seeing image thumbnails |
| 📋 List | Small icons in a vertical list | Seeing many files at once |
| 📊 Details | Name + size + type + date modified | Sorting and finding files by properties |
2.1.5 Searching for Files ICDL 2.1.5
Search by: file name (all or part), file content, or date modified.
* means "anything". Example: *.pdf finds all PDF files. report* finds all files starting with "report".2.2.1–2.2.6 Organising Files & Folders ICDL 2.2
Right-click in empty space → "New Folder" → type a name → press Enter. Or use Ctrl + Shift + N.
Good naming: "Math_Homework_2025" ✅ "stuff" ❌ "asdfgh" ❌
Select the item → press F2 → type new name → press Enter. Or right-click → Rename.
Rules: Don't use these characters in names: / \ : * ? " < > |. Don't change the file extension accidentally!
Adjacent (next to each other): Click the first file, hold Shift, click the last file.
Non-adjacent (scattered): Hold Ctrl and click each file you want.
Select all: Ctrl + A
| Action | Shortcut | What Happens |
|---|---|---|
| Copy | Ctrl + C | Makes a duplicate — original stays |
| Cut (Move) | Ctrl + X | Moves the file — original is removed |
| Paste | Ctrl + V | Places the copied/cut item in current location |
| Undo | Ctrl + Z | Reverses the last action |
You can also copy/move between different drives!
Delete: Select → press Delete key → file goes to Trash.
Restore: Open Trash → right-click the file → "Restore" / "Put Back".
Permanent delete: Shift + Delete (skips Trash — be careful!).
Empty Trash: Right-click Trash icon → "Empty Trash" (gone forever!).
In the File Manager, click column headers to sort:
By Name: A→Z (ascending) or Z→A (descending)
By Size: Smallest to largest or largest to smallest
By Type: Groups similar file types together
By Date Modified: Newest first or oldest first
2.3 Storage Media & Data Sizes ICDL 2.3
| Storage Type | Internal/External | Speed | Typical Size |
|---|---|---|---|
| 🖴 Internal Hard Drive (HDD) | Internal | Medium | 500 GB – 4 TB |
| ⚡ Solid State Drive (SSD) | Internal / External | Very Fast | 128 GB – 2 TB |
| 🔌 USB Flash Drive | External, portable | Medium | 4 GB – 256 GB |
| 💳 Memory Card (SD/MicroSD) | External, tiny | Medium | 8 GB – 1 TB |
| 🌐 Network Drive (NAS) | Network | Depends on network | 1 TB – 100+ TB |
| ☁️ Cloud Storage | Online | Depends on internet | 5 GB – Unlimited (paid) |
| 💿 External Hard Drive | External | Medium–Fast | 500 GB – 5 TB |
Data size units:
| Unit | Abbreviation | Size | Real-World Example |
|---|---|---|---|
| Kilobyte | KB | 1,000 Bytes | A short email or text file |
| Megabyte | MB | 1,000 KB | One photo (3–5 MB) or one song |
| Gigabyte | GB | 1,000 MB | About 250 songs or a short movie |
| Terabyte | TB | 1,000 GB | About 500 hours of video |
| Petabyte | PB | 1,000 TB | All the photos on Facebook! |
2.3.3 Viewing File & Folder Properties ICDL 2.3.3
Right-click any file or folder → choose "Properties" to see: name, size, location (path), type, and last modified date.
2.4 Managing Applications ICDL 2.4
Install on Linux:
- Open "Software Center" (Ubuntu Software / GNOME Software)
- Search for the app → click "Install" → enter password if needed
Or via Terminal: sudo apt install gimp
Uninstall: Software Center → "Installed" tab → find the app → click "Remove".
If a program stops responding (freezes):
Method 1: Right-click the app in the taskbar → "Force Quit" or "Close"
Method 2: Press Ctrl + Alt + Delete → select the frozen app → "End Task" / "Kill"
Method 3 (Linux): Open Terminal → type xkill → click on the frozen window
| Action | Shortcut |
|---|---|
| Capture full screen | Print Screen (PrtSc) |
| Capture active window only | Alt + Print Screen |
| Capture a selected area | Shift + Print Screen |
The screenshot is usually saved automatically to your Pictures folder or copied to the clipboard.
🎮 Activity: Match the Extension!
Click an extension on the left, then click its matching type on the right:
3.1.1 What is a Network? ICDL 3.1.1
A network is two or more computers connected together so they can share data, applications, and devices (like printers).
| Network Type | Range | Example |
|---|---|---|
| LAN (Local Area Network) | Small area — one building or room | School computer lab, home wifi |
| WAN (Wide Area Network) | Large area — cities or countries | The Internet is the biggest WAN! |
| WLAN (Wireless LAN) | Small area — using wifi | Wifi in your classroom |
3.1.2 Downloading & Uploading ICDL 3.1.2
⬆️ Uploading = Sending data FROM your computer TO the internet. (Example: posting a photo on social media)
3.1.3 The Internet & Its Uses ICDL 3.1.3
The Internet is a massive global network connecting billions of computers and devices. It's used for:
3.2.1 Ways to Connect ICDL 3.2.1
| Connection Type | How It Works | Speed | Pros & Cons |
|---|---|---|---|
| 🔌 Wired (Ethernet) | Physical cable from computer to router | Very fast & stable | ✅ Reliable, secure. ❌ Not portable. |
| 📶 Wireless (WiFi) | Radio waves from a router | Fast (range ~50m) | ✅ No cables, portable. ❌ Can be intercepted. |
| 📱 Mobile Data (4G/5G) | Cell towers via your phone's SIM card | Medium–Fast | ✅ Works anywhere with coverage. ❌ Data limits, costs money. |
3.2.2 WiFi Security ICDL 3.2.2
🔓 Open WiFi: No password needed. Anyone can join AND potentially see your data. Found in cafes and public places. Avoid entering passwords or personal info on open wifi.
To connect to WiFi:
- Click the network/wifi icon in the system tray (top-right corner)
- A list of available networks appears — choose yours
- Enter the password if it's a protected network
- Wait for the connection icon to show you're connected
To disconnect: Click the wifi icon → click your network → "Disconnect".
4.1.1 Key Web Terms ICDL 4.1.1
| Term | Full Name | Meaning |
|---|---|---|
| WWW | World Wide Web | A system of web pages accessed through the internet using a browser. Not the same as the internet — the internet is the network; the web is the content on it. |
| URL | Uniform Resource Locator | The address of a web page. Example: https://www.libreoffice.org. Type it in the address bar to visit the page. |
| Hyperlink | — | A clickable link that takes you to another page. Usually blue and underlined. Can also link to files, emails, or sections within a page. |
4.1.2–4.1.4 Searching the Web ICDL 4.1.2–4.1.4
A search engine is a tool that finds web pages based on your search words. Common search engines: Google, DuckDuckGo (privacy-focused!), Bing.
Search techniques:
| Technique | How | Example |
|---|---|---|
| Simple keyword | Type one or more words | LibreOffice download |
| Exact phrase | Put words in "quotes" | "open source software" |
| Image search | Click "Images" tab in search | Find pictures of the Eiffel Tower |
| Filter by date | Use search tools → select date range | Find results from the last week only |
| Filter by type | Use search tools → file type | Find only .pdf results |
4.2 Managing Online Information ICDL 4.2
Bookmark = Save a web page address so you can revisit it quickly.
Add bookmark: Press Ctrl + D or click the star icon ⭐ in the address bar.
Create bookmark folder: Bookmarks menu → "Manage Bookmarks" → "New Folder" → name it (e.g., "School Research").
Delete: Right-click the bookmark → "Delete".
When you click a download link, the browser saves the file (usually to your Downloads folder).
Choose where to save: Some browsers ask each time. In Firefox: Settings → General → "Always ask you where to save files".
Check downloads: Press Ctrl + J to see your download history.
Press Ctrl + P to open print dialog. You can:
• Preview — see how the page will look on paper
• Print entire page or just a selection (highlight text first, then choose "Selection" in print options)
• Save as PDF — choose "Print to PDF" as the printer
Copyright = Legal protection for creative work (text, images, music, videos). The creator controls how it's used.
Intellectual Property (IP) = Ideas and creations that belong to someone — inventions, designs, brands, artwork.
Important rules:
• Always acknowledge sources — say where you got information from
• Ask permission before using someone else's work
• Use free/open-source content when possible (Creative Commons licenses)
• Never copy and pretend it's your own work (that's plagiarism!)
4.3 Browser Settings ICDL 4.3
| Setting | What It Is | How to Change (Firefox) |
|---|---|---|
| 🏠 Home Page | The page that loads when you open the browser or click the Home button | Settings → Home → Custom URL |
| 🪟 Pop-ups | Small windows that open automatically (often ads). Usually annoying — block them! | Settings → Privacy → Block pop-up windows ✅ |
| 🍪 Cookies | Small files websites save on your computer to remember you (login, preferences). Can track you across sites. | Settings → Privacy → Cookies → choose level |
| 🧹 Clear History | Delete browsing history, temp files, saved passwords, form data | Ctrl + Shift + Delete |
5.1.1 Email ICDL 5.1.1
Email (Electronic Mail) lets you send messages, files, and images to anyone with an email address. It's the most important professional communication tool.
username@domain.comExample:
student@alinli.org — "student" is the username, "alinli.org" is the domain (the email provider).Email applications: Thunderbird (open-source!), Outlook, or web-based email (Gmail, ProtonMail).
5.1.2–5.1.3 Other Communication Tools ICDL 5.1.2–5.1.3
| Tool | Features | Open-Source Examples |
|---|---|---|
| 💬 Messaging | Real-time text chat, emojis, file sharing | Element (Matrix), Signal |
| 📞 Audio Calls | Voice calls over internet (VoIP) | Jitsi Meet, Mumble |
| 📹 Video Calls | Face-to-face communication via webcam | Jitsi Meet, BigBlueButton |
| 👥 Social Networking | Share posts, photos, connect with people | Mastodon, Diaspora, Pixelfed |
| 💭 Forums | Discussion boards organized by topics/threads | Discourse, Reddit-style platforms |
5.1.4 Good Communication Practices ICDL 5.1.4
✅ Use the right tool for the situation (email for formal, messaging for quick chats)
✅ Match your tone to the audience (teacher vs. friend)
✅ Be A-B-C: Accurate, Brief, Clear
❌ Never share private/sensitive information unnecessarily
❌ Never send inappropriate content
✅ Follow your school's usage policies
5.2 Sending Email ICDL 5.2
| Field | Purpose | Who Can See It? |
|---|---|---|
| To: | Main recipient(s) | Everyone |
| Cc: (Carbon Copy) | Others who should see the email "for information" | Everyone |
| Bcc: (Blind Carbon Copy) | Hidden recipients — others can't see them | Only the Bcc person & sender |
| Subject: | Brief title describing the email's topic | Everyone |
| Body: | The main message content | Everyone |
| Attachments: | Files added to the email (📎) | Everyone |
5.3 Receiving & Replying ICDL 5.3
| Action | What It Does | When to Use |
|---|---|---|
| ↩️ Reply | Sends response to the sender only | When only the sender needs your answer |
| ↩️↩️ Reply All | Sends to sender AND everyone in To/Cc | When everyone needs to see your response |
| ➡️ Forward | Sends the email to someone new | When sharing info with someone not in the original email |
Attachments received: Open an attachment by clicking it. Save it by right-clicking → "Save As" → choose a location.
5.4–5.5 Email Management ICDL 5.4–5.5
Out of Office Reply: Automatic reply sent when you're away (vacation, holiday). Set in Settings → "Out of Office" or "Auto-Reply".
Mark as Read/Unread: Right-click → "Mark as Read" or "Mark as Unread". Unread emails appear bold.
Flag an email: Click the flag icon to mark important emails for follow-up. Click again to remove the flag.
Contacts: Create, update, and delete contacts (name + email). Group contacts into distribution lists to email many people at once.
Search: Search emails by sender, subject, or content using the search bar.
Sort: Click column headers to sort by name, date, or size.
Folders/Labels: Create folders (like "School", "Personal") to organise emails. Drag emails into folders.
Delete: Select email → press Delete → goes to Trash. Restore from Trash if needed.
Junk/Spam: Mark unwanted emails as "Junk". Move legitimate emails OUT of junk if they ended up there by mistake.
5.6 Using Calendars ICDL 5.6
Digital calendars help you schedule events, meetings, and reminders. In Thunderbird, the calendar is built-in!
| Action | How |
|---|---|
| 📅 Create a meeting/event | Click the date/time → add title, location, time, description → Save |
| ✏️ Update an event | Double-click the event → edit details → Save |
| ❌ Cancel/Delete an event | Right-click → Delete. If others are invited, they'll get a cancellation notice. |
| 👥 Add invitees | When creating: add people's emails in "Invite Attendees" field |
| 🏢 Add resources | Add meeting room or equipment in the resources field |
| ✅ Accept / ❌ Decline | When you receive a meeting invitation, click Accept, Decline, or Tentative |
📖 Internet References
6.1.1 Threats to Computers & Data ICDL 6.1.1
6.1.2 How to Protect Your Computer ICDL 6.1.2
| Protection Method | What It Does |
|---|---|
| 🛡️ Anti-virus software | Scans for and removes malware. Keep it updated! (ClamAV is open-source) |
| 🔄 Update software regularly | Updates fix security holes. Update your OS, browser, and all apps |
| 🚫 Don't open unknown links/files | Don't download from unknown sources. Don't click suspicious email links |
| 🔐 Use encryption | Scrambles your data so only authorized people can read it |
| 🔑 Use strong passwords | Long (12+ characters), mix of uppercase, lowercase, numbers, symbols |
| 💾 Back up regularly | Copy important files to an external drive or cloud storage |
6.1.3 Staying Safe Online ICDL 6.1.3
🔒 Check for https:// and the padlock icon before entering any personal info
🛒 Only buy from secure, reputable websites
🤐 Don't share unnecessary private or financial information
🚪 Always log off from websites when done (especially on shared computers)
📧 Be aware of phishing — fake emails pretending to be from banks, companies, etc.
🎣 Check the sender's actual email address — phishing emails often have suspicious addresses
6.1.4 Using Anti-Virus Software ICDL 6.1.4
Anti-virus software protects your computer by scanning files for malware. On Linux, ClamAV is a free, open-source anti-virus.
- Install anti-virus software (ClamAV:
sudo apt install clamav) - Update the virus definitions regularly
- Run a full system scan periodically
- Scan any new USB drives or downloaded files before opening
6.2.1 Physical Well-Being ICDL 6.2.1
6.2.2 Accessibility Options ICDL 6.2.2
Computers include features to help people with different abilities:
| Feature | What It Does | Who It Helps |
|---|---|---|
| 🗣️ Voice Recognition | Control the computer using your voice | People who can't use a keyboard/mouse |
| 📖 Screen Reader | Reads text on screen out loud (Orca in Linux) | People who are blind or have low vision |
| 🔍 Screen Magnifier | Zooms in on parts of the screen | People with low vision |
| ⌨️ On-Screen Keyboard | A virtual keyboard you click with the mouse | People who can't use a physical keyboard |
| 🎨 High Contrast | Makes text and edges much more visible | People with visual impairments |
6.3 Environment — Green IT ICDL 6.3
• Turn off computers when not in use (don't just leave them on all day!)
• Adjust display settings: reduce brightness, use shorter screen timeout
• Use power saving mode: Settings → Power → enable energy saver
• Disable unused services: Turn off Bluetooth and WiFi when not needed
♻️ Recycling:
• Recycle old computers, phones, batteries, printer cartridges, and cables at e-waste facilities
• Reduce paper: Print only when necessary; use both sides; use digital documents
• Donate working old devices to schools or charities
Alin Li ICDL Academy — Computer & Online Essentials · Complete Module