Cambridge Syllabus Notes

4 Networks and the Effects of Using Them

Extranet

An extranet is a private network that extends a company’s intranet to external users such as suppliers, partners or customers. Think of it like a shared library between two schools – only people who have a key can enter.

🔐 Access control: Only authorised users can log in.
📁 Shared resources: Documents, project plans, and real‑time data.
💬 Communication: Secure messaging, forums, and video calls.

Uses: Streamlining supply chain, collaborative projects, and customer support.

Purpose: Increase efficiency by giving trusted outsiders safe access to specific information.

Exam Tip: Remember that an extranet extends an intranet but does not expose the entire internal network to the public. Use the phrase “controlled external access” in your answers.

Intranet

An intranet is a private network used by an organisation’s employees. It’s like a school’s internal network – only students and staff can access it.

📚 Internal knowledge base: Policies, manuals, and training materials.
🗂️ File sharing: Centralised storage for documents.
🤝 Collaboration tools: Internal chat, project boards, and calendars.

Uses: Managing HR, IT support, and internal communications.

Purpose: Keep sensitive information secure while facilitating easy access for staff.

Exam Tip: Highlight that an intranet is not accessible from the outside world and that its main goal is internal efficiency and security.

Internet

The Internet is a global network that connects millions of private, public, academic, business, and government networks. Think of it as the world’s biggest library – open to everyone, but with varying levels of access.

🌐 Open access: Anyone with a device can connect.
🔗 Hyperlinks: Navigate between pages instantly.
📡 Services: Email, social media, e‑commerce, cloud storage.

Uses: Education, entertainment, commerce, and communication worldwide.

Purpose: Facilitate the free flow of information and services across the globe.

Exam Tip: Emphasise that the Internet is a public network with no single owner and that it relies on protocols like TCP/IP to function.

Key Differences at a Glance

Network Type	Access	Typical Users	Main Purpose
Extranet	Restricted to authorised external users	Suppliers, partners, customers	Secure collaboration outside the organisation
Intranet	Internal only	Employees, staff	Internal communication & information sharing
Internet	Open to everyone	All users worldwide	Global information exchange & services

Exam Preparation Checklist

📌 Define each network: Use clear, concise language.
📌 Compare characteristics: Use a table or bullet points.
📌 Provide real‑world examples: School library, company portal, global web.
📌 Explain security aspects: Access control, authentication.
📌 Use exam keywords: “controlled external access”, “public network”, “internal efficiency”.
📌 Practice with past papers: Focus on multiple‑choice and short answer questions.

Know and understand characteristics, uses and purpose of an extranet, intranet and the internet