(1) (Password Authentication Protocol) An access control protocol for dialing into a network that provides only basic functionality. When the client logs onto the network, the network access server (NAS) requests the username and password from the client and sends it to the authentication server for verification. Since the password is sent over the line unencrypted from the client, it provides password checking, but is not secure from eavesdropping. See CHAP and PPP.

(2) (Printer Access Protocol) A printing protocol for the Macintosh introduced in 1985 by Apple with the advent of its LaserWriter laser printer. It provides bi-directional capability, sending PostScript commands between the printer and the requesting client or server via AppleTalk or over TCP/IP with third-party software. See printing protocol.