What Is a Computer Network?

Start with the idea

A computer network is a group of devices that can exchange data. The devices might be in one room, one building, or spread across the world.

Know the common parts

• Hosts such as computers, phones, and printers
• Links such as Wi-Fi radio or Ethernet cable
• Intermediary devices such as switches, routers, and access points
• Shared rules (protocols) so both sides understand the messages

Think in layers of scale

A home Wi-Fi setup is a local area network (LAN). The internet is a huge collection of networks that agree to forward traffic between one another.

Focus on the job, not the gear

Networking is about delivering the right data to the right place reliably enough for the task. A video call needs low delay; a file download mainly needs throughput and correctness.