Real general explanation (somewhat techy.. but im sleepy so bare.... i mean BEAR with me: Take your basic $5.00 Walmart phone, those plain old wall phones. These telephones once plugged in receive power from the phone company (this is a good tip to remember in the event of a power outage!, these basic phones should still work). Here's how: A telephone is basically a 2 wire electronic circuit, with a few main components: A (flash) hook switch, a mic, a ringer, and a speaker. The phone company supplies a very low voltage level (low enough so you can't get shocked), over the pair of copper wires.