Networking · 01 · 3 min read

What is a network?

Two or more devices connected so they can share data. The internet is just a network of networks.

Sizes of networks

PAN — your phone and earbuds (a few metres).
LAN — a home, office or classroom.
MAN — a whole city, e.g. a university campus network.
WAN — countries and continents; the internet is the biggest WAN.

The pieces

Every network has endpoints (laptops, phones, servers), links that carry the signal (copper cable, fibre, radio), and devices that move traffic along — switches inside a network, routers between networks. Rules called protocols make sure everyone speaks the same language.

How they are shaped

The layout is called a topology. Today almost every LAN is a star: all devices plug into one central switch. If one cable breaks, only that device drops off.