Understanding analogue and digital signals is not simply comparing one technology to another. The real difference is in the actual product and its features. As with any development, both analogue and digital technology have benefits and downfalls.
Plain Old Telephone Service (POTS) lines, or analogue phone lines, are those ordinarily found in the home or small office. Large, multi-line corporate telephone systems typically use digital phone systems.
Cordless phones themselves are analogue, though the signals from handset to base may be either analogue or digital. While analogue cordless service remains less expensive, it does not protect transmissions from eavesdroppers as digital lines do. Digital technology breaks signals into binary code and recreates them on the opposite end, providing clear, distortion-free cordless conversation.
Digital telephone lines carry lower voltages than analogue lines but still pose a risk to analogue equipment. Phone, fax or modem lines should not connect directly through a digital phone system, as the equipment may not function properly.