Of, pertaining to, or being a connection that uses the public switched telephone network rather than a dedicated circuit or some other type of private network.
Thus, we can add up numbers in our head, remember a telephone number long enough to dial it, and remember the first half of a sentence while reading or listening to the second half.
Dial Service, a telephone counseling service for children in Japan, says that recently many children who have no pressing problems and want no advice are calling up just to talk to someone about their day.