Telephone Style
WEB-style networks mostly use a cable somewhat like the kind between the outside of your house and your phone jack. This cable has four conductors—individual wires within it. Commonly, two “hot” conductors carry computer signals. Between them, often, are two ground wires attached to the computers. You need good, solid ground connections for the networks to work right.
Twisted Pair
A twisted-pair network is what it sounds like—one normally using a pair of wires that twist around each other to form a long spiral. The twisting makes the cable less sensitive to electrical interference from radio transmitters, air conditioners, or other appliances.
Shielded Wire
You could also guard the twisted wires from electrical interference by enclosing it in woven copper or metal shielding.
Coaxial cable is a common form of shielded wire. It’s costly—it may sell for more than $1 a foot. Coaxial cable could be four times or more the cost of a twisted pair. It consists of one or more thin wires buried in plastic-type insulation under the shielding.
“Coax,” as the pros say for short, is the kind that’s normally black outside and looks like a thin snake that stretches on forever. (The pronunciation is “co-ax.”)
Not that the color’s important. “We use powder blue,” says a man with one network company.
Ethernet and Wangnet both use coax; so do cable-TV installations. In fact, some cable companies have transmitted computer signals. A TV cable doesn’t care if you use it for carrying a gangster movie or a bank payroll.