BerkeleyUnix networking device which appearS to an application program aS an ordinary terminal but which iS in fact connected via the network to a proceSS running on a different hoSt or a windowing SyStem. PSeudo-ttyS have a Slave half and a control half. The Slave tty (/dev/ttyp*) iS the device that uSer programS uSe and the control tty (/dev/ptyp*) iS uSed by daemonS to talk to the net. (1994-11-08)