Module 1 – Computer Essentials

Lesson 4 – Networks and Internet Essentials

This lesson explains how computers connect to each other, how the internet works, how to use web browsers
effectively, and how to stay safe online. Understanding connectivity and online tools is essential for work,
study and communication.

Learning outcomes

By the end of this lesson, you should be able to:

• Explain what a computer network is and list different network types.
• Describe common networking devices such as routers, modems and switches.
• Compare wired and wireless connections and identify secure Wi-Fi types.
• Explain what the internet is and list common online services.
• Use a web browser and search engine effectively.
• Read and understand a basic URL (web address).
• Recognise common online communication tools.
• Apply safe and responsible internet practices, including basic security and digital well-being.

Quick warm-up

Think about how you used the internet in the last 24 hours. Did you…

• Send a message or email?
• Watch a video or use social media?
• Check a map, timetable or online banking?

1. What is a computer network?

A computer network allows devices to connect and communicate with each other. A network can share:

• Files and folders
• Printers and hardware
• Internet connections
• Applications and services

Types of networks

• LAN (Local Area Network) – covers a small area such as a home, school or office.
• WAN (Wide Area Network) – covers large areas such as cities or countries. The internet is the
  world’s largest WAN.
• WLAN (Wireless LAN) – uses Wi-Fi instead of cables.

Network devices

• Router – connects devices to the internet.
• Modem – communicates with your internet service provider (ISP).
• Switch – connects multiple wired devices.
• Access Point – provides Wi-Fi coverage.

2. Connecting to a network

Wired connections

• Use Ethernet network cables.
• More stable and secure than Wi-Fi.
• Often used for office desktops or servers.

Wireless connections (Wi-Fi)

• Connects using radio signals.
• Suitable for laptops, tablets and smartphones.
• More flexible but can be affected by interference.

Wi-Fi security types

• WPA2 / WPA3 – secure and recommended.
• Open networks – no password; avoid for confidential work.

3. What is the Internet?

The internet is a global network of computers linked together. It allows people to:

• Browse websites
• Send and receive emails
• Use social media
• Stream videos and music
• Shop and bank online
• Work and learn remotely

4. Web browsers

A web browser is a program used to access websites. Common browsers include:

• Google Chrome
• Microsoft Edge
• Mozilla Firefox
• Safari (Mac/iPhone/iPad)

Browser features

• Address bar – enter website addresses (URLs).
• Tabs – open multiple websites at once.
• Back / Forward – navigate between pages.
• Refresh – reload the current page.
• Bookmarks – save favourite websites.
• History – shows previously visited pages.

5. Search engines

Search engines help you find information online. Examples include:

• Google
• Bing
• DuckDuckGo

Search tips

• Use keywords, not full sentences.
• Use quotation marks for exact phrases: “ICDL online course”
• Use minus to exclude words: jaguar -car
• Use filters for Images, Videos, News or time range.

6. URLs and website structure

A web address (URL) contains several parts. Example:

https://www.example.com/page

• https:// – secure protocol
• www.example.com – domain name
• /page – specific page on the site

7. Online communication tools

• Email – send messages and attachments.
• Instant messaging – WhatsApp, Teams, Slack.
• Video calls – Zoom, Google Meet, Teams.
• Social media – Facebook, Instagram, X.
• Cloud collaboration – Google Drive, OneDrive, SharePoint.

8. Safe and responsible internet use

Online threats

• Phishing – fake emails/messages that attempt to steal information.
• Malware – viruses, ransomware, spyware.
• Fake websites – designed to trick users.
• Insecure public Wi-Fi – data can be intercepted.

Safe practices

• Check website security (look for https and padlock).
• Use strong, unique passwords.
• Avoid suspicious links or attachments.
• Do not share personal information online.
• Log out when using public devices.
• Use antivirus software and keep it updated.

Digital well-being

• Take regular breaks to avoid eye strain.
• Use screen time tools to manage usage.
• Maintain a healthy online/offline balance.
• Avoid harmful or inappropriate content.

9. Practical Activity

Try the following tasks on your own device (where possible):

• Connect a device to a Wi-Fi network and check the security type (WPA2/WPA3).
• Open your web browser and bookmark three useful websites.
• Use a search engine to find a PDF user guide for a device or app.
• Check whether a website is secure by inspecting the URL.
• Check your internet speed using an online speed test.