Vonage routes your phone calls over the Internet using Voice over Internet Protocol, rather than telephone lines. But even though your phone uses the Internet, it has nothing to do with your computer. In fact, your computer doesn't have to be on to use Vonage. The people you call don't need to have Vonage or the Internet to get your call - just a phone. And when someone calls you, your phone rings as usual.
Visit Vonage at http://www.vonage.com