VoIP telephone system utilizes Internet Protocol to make calls. Instead of using telephone lines, all communication data is turned into packets and sent over the IP network. Placing calls over traditional phone lines means that a line is taken up by the two callers using it to communicate. Since there are only so many lines that can be installed, calls placed over landlines, especially if they are long-distance, are expensive. But using the Internet to relay call data circumvents this problem, making domestic and long-distance calls cheaper overall and sometimes even free.