A group of interconnected devices that communicate and share resources with each other.
Network Scale
- Wide-Area Network (WAN)
Spans > 30 km. Operated by telecom providers. - Metropolitan Area Network (MAN)
Spans up to ~50 km. Covers a city region. Operated by telecom providers. - Local-Area Network (LAN)
Spans < 1 km. Run by individual organizations.
They were traditionally used distinct technologies. Now the differences between them is diminishing.