What is a computer network?
A computer network is a collection of computers connected by communication links.
Why are computer networks important?
- Resource sharing
- Social impact
- Easy access to knowledge and education
- Economic impact
Communication Links
There are 4 types of communication links:
- Point-to-Point
- Broadcast
- Multicast
- Unicast
| Link Type | What it does | Example |
|---|---|---|
| Point-to-Point | Private link, goes to only 1 device. | Text message, Ethernet |
| Broadcast | Public link, spreads to all devices. | Wi-Fi |
| Multicast | Smaller broadcast that only spreads out to a certain group of devices. | |
| Unicast | A ptp link inside a broadcast system. |
Core components of a computer network
There are 4 core components to a computer network:
- Application
- Nodes
- Links/Channels
- Communication devices
The image below is an over-simplified diagram of these core components.
| Component | Example |
|---|---|
| Application | Skype, Chrome |
| Nodes | PC, laptop, mobile |
| Links/Channels | links connecting nodes together |
| Communication devices | routers, switches, repeaters, NIC |