In this illustration, we see a single link-layer switch blow up to large scale, and along one side of the switch we see sixteen ports arranged and numbered like this:

Ports 1 and 16 are white. Ports 2-8 are light blue, and ports 9-15 are medium blue.

The numbered ports (excepting 1 and 16) each have computers connected to them, and the computers appear below forming two separate networks. The network on the left, connected to the light blue ports, is labeled "Electrical Engineering (VLAN ports 2-8)." The network on the right, connected to the medium blue ports, is labeled "Computer Science (VLAN ports 9-15)."