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

Topic: Networks and the Effects of Using Them

Objective

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

Key Definitions

• Internet – A global public network that connects millions of private, public, academic, business and government networks.
• Intranet – A private network that uses Internet protocols (TCP/IP) and technologies (e.g., web browsers) but is restricted to an organisation’s internal users.
• Extranet – A controlled extension of an intranet that provides limited access to external users such as partners, suppliers or customers.

Characteristics

• Ownership:
  • Internet – No single owner; collectively owned by many organisations and governments.
  • Intranet – Owned and managed by a single organisation.
  • Extranet – Owned by a single organisation but access is granted to selected external parties.
• Access control:
  • Internet – Open to anyone with an Internet Service Provider (ISP) connection.
  • Intranet – Restricted to authorised internal users (e.g., employees).
  • Extranet – Restricted to authorised internal users and specific external users.
• Security level:
  • Internet – Lowest; relies on firewalls, encryption, VPNs, etc.
  • Intranet – Higher; protected by internal firewalls, authentication and policies.
  • Extranet – Highest; combines intranet security with additional authentication for external users (e.g., VPN, two‑factor).
• Typical technologies: TCP/IP, HTTP/HTTPS, DNS, VPN, firewalls, SSL/TLS.

Uses and Purposes

• Internet
  • Research and information retrieval.
  • Communication (email, social media, video conferencing).
  • E‑commerce and online services.
  • Cloud computing and software‑as‑a‑service.
• Intranet
  • Internal communication (intranet portals, internal email).
  • Document management and shared repositories.
  • Internal applications (HR, payroll, inventory).
  • Collaboration tools for project teams.
• Extranet
  • Supplier and partner collaboration (order processing, inventory sharing).
  • Customer self‑service portals (account information, support tickets).
  • Secure data exchange with external consultants or contractors.
  • Joint development environments for multiple organisations.

Comparison Table

Aspect	Internet	Intranet	Extranet
Scope	World‑wide public network	Private network within an organisation	Private network extended to selected external users
Ownership	Collective (no single owner)	Owned by the organisation	Owned by the organisation
Access	Open to anyone with ISP	Restricted to internal staff	Restricted to internal staff + authorised external parties
Security	Basic to moderate (firewalls, encryption)	Higher – internal firewalls, authentication	Highest – intranet security + VPN, two‑factor, access lists
Typical Users	General public, businesses, governments	Employees, management	Suppliers, partners, customers, contractors
Common Uses	Web browsing, email, streaming, cloud services	Internal portals, document sharing, HR systems	Partner portals, supply‑chain integration, client support sites

Advantages and Disadvantages

1. Internet
   • Advantages: Global reach, vast information resources, many services.
   • Disadvantages: Lower security, risk of cyber‑attacks, information overload.
2. Intranet
   • Advantages: Secure environment, tailored to organisational needs, improves internal communication.
   • Disadvantages: Requires maintenance, limited to internal users, may become siloed.
3. Extranet
   • Advantages: Facilitates collaboration with external partners, improves supply‑chain efficiency, controlled access.
   • Disadvantages: More complex security management, higher setup cost, need for strict access policies.

Summary

The Internet, intranet and extranet are three distinct network environments that share common technologies but differ in scope, ownership, access control and security. Understanding these differences enables learners to select the appropriate network for a given purpose, whether it is public communication, internal collaboration, or secure interaction with external stakeholders.