Ethernet is a computer networking protocol. Before Ethernet, computers were connected using a hodgepodge of various systems, a digital Tower of Babel.
Background
Bob Metcalfe invented Ethernet at Xerox PARC. However, Xerox failed to commercialize the technology. Metcalfe left and worked on his own Digital (see minicomputers) and Intel to set Ethernet as a networking standard. Eventually, the industry adopted Ethernet as a standard labeling it IEEE 802.3.
Ethernet’s advantage is that it is radically simpler and cheaper than prior “better” methods.
Think of information flowing from one computer to another. Information is broken down into small pieces, called packets, then sent on their way. The receiving computer reassembles the packets. For example, this page is a series of packets. A server broke it into packets then your computer or phone reassembled it.
Other networking methods went to great lengths to avoid the packets from colliding. Ethernet simply allows them to occasionally collide, which means they disappear, then resends when that happens.
Think of Ethernet as an enormous highway with little traffic control where cars, carrying information, sometimes collide and destroy one another. When this happens, the sender simply generates and resents a new packet. This was vastly less complicated and less expensive than trying to avoid collisions.
Ethernet Thrives After Xerox PARC
After Xerox PARC, in 1979, Metcalfe founded 3Com and formulated Metcalfe’s law, that computer networks become exponentially more useful with more nodes.
Metcalfe lost 3Com in a boardroom fight though the company left him extremely wealthy. Xerox made little or no money from Ethernet, but Metcalfe’s 3Com grew into a Fortune 500 company making him extremely wealthy.
Today, Wifi remains a wireless version of Ethernet.