Ethernet was developed in 1972 as a way to connect
newly invented computers to newly invented
laser printers. It was recognized even at that time
as a remarkable technology breakthrough.
However, very few people would have wagered
that the ability to connect computers and devices
would change human communication on the same
scale as the invention of the telephone and change
business on the scale of the Industrial Revolution.
Several competing protocols have emerged since
1972, but Ethernet remains the dominant standard
for connecting computers into local-area networks
(LAN). For many years Ethernet was dominant in
home networks as well. Ethernet has been mostly
replaced by wireless technologies in the home networking
market. Wireless or Wi-Fi is covered in
Part VIII, “Mobility.”