Computer networks are a core topic in IB Computer Science because they explain how devices communicate and share data. Students are expected to understand what a network is, why networks exist, and how different types of networks are classified based on size and purpose.
In IB exams, vague definitions such as “computers connected together” are not enough. Clear explanations using correct terminology are required.
What Is a Computer Network?
A computer network is a group of devices that are connected so they can:
- Share data
- Share resources
- Communicate with each other
Devices on a network may include:
- Computers
- Servers
- Printers
- Smartphones
- IoT devices
Networks allow efficient communication and reduce the need for duplicated hardware and data.
Why Computer Networks Are Used
Networks exist to:
- Enable file sharing
- Allow shared access to hardware (printers, storage)
- Support communication (email, messaging)
- Allow remote access to data and services
In IB Computer Science, networks are often linked to efficiency, collaboration, and scalability.
Local Area Network (LAN)
A Local Area Network (LAN) covers a small geographical area.
Examples include:
- A home network
- A school network
- An office building
Key characteristics of LANs:
- High data transfer speeds
- Owned and managed by a single organisation
- Low latency
- Usually use wired Ethernet or Wi-Fi
LANs are commonly used to:
- Share files locally
- Connect computers to printers
- Access local servers
In IB exams, LANs are associated with speed and control.
Wide Area Network (WAN)
A Wide Area Network (WAN) covers a large geographical area, often spanning cities, countries, or continents.
The most common example of a WAN is:
- The Internet
Key characteristics of WANs:
- Connect multiple LANs
- Use public or leased communication links
- Lower speeds compared to LANs
- Higher latency
WANs allow organisations to:
- Connect branch offices
- Share data across long distances
- Provide global access to services
In IB Computer Science, WANs are linked to scale and long-distance communication.
Personal Area Network (PAN)
A Personal Area Network (PAN) covers a very small area, usually around a single user.
Examples include:
- Bluetooth connections
- Wireless headphones
- Smartwatches connected to phones
Key characteristics of PANs:
- Short range
- Low power usage
- Designed for personal devices
PANs prioritise convenience and portability over speed.
Comparing LAN, WAN, and PAN
IB students should be able to compare networks based on:
- Size
- Speed
- Ownership
- Purpose
Clear comparisons help demonstrate understanding.
Common Student Mistakes
Students often:
- Confuse LAN and WAN
- Forget PAN entirely
- Describe networks without examples
- Ignore speed and range differences
Precision earns marks.
Final Thoughts
LANs, WANs, and PANs represent different ways devices are connected based on distance and purpose. Understanding these distinctions allows IB Computer Science students to explain how modern communication systems work — from personal devices to the global internet.
