Packer - A program to compress multiple files into a single file, such as PKZIP, ARC or LHARC

Packet - The unit of data sent across a network.

Packet Loss - Packet Loss measures the reliability of a connection. A known chunk of data is sent to the router and then the router is supposed to send the same data back unaltered (echo). If the packet returns intact then there was 0% packet loss and that is good. If the packet returns with half of its data garbled or missing then that is 50% packet loss, which is poor. 100% packet loss means the packet never returned.

Parity - An error detection method used in both communications and computer memory checking to determine character validity. Communications now makes use of more efficient "block" checking although parity must still be matched in a communication session for transfer to take place correctly. Host communication in the BBS environment omits parity checking (no parity).

Password - A secret combinations of letters and other symbols needed to login to a computer system.

Peer-to-Peer - A simple type of networking that doesn’t include a dedicated server (central computer). A PC on a peer-to-peer LAN may simultaneously serve as your workstation and make resources available to other users.

PICS - Platform for Internet Content Selection - PICS is a technology that allows Web browsers to read content ratings of Web sites, but it is not a rating system itself.

PlugIn - A program that works with browsers to play audio and video.

PGP - (Pretty Good Privacy) - an encryption scheme which uses the "public key" approach - messages are encrypted using the publicly available key, but can only be deciphered by the intended recipient via the private key.

POP (Post Office Protocol) A system by which a mail server on the Net lets you pick up your mail and download it to your computer. The POP server is the computer from which you pick up your mail.

PPP (Point-to-Point Protocol) A scheme for connecting your computer to the Internet via a phone line.

Port - 1.A socket at the back of a computer used to plug in external devices such as a modem, mouse, scanner, or printer. 2.In a communications network, a logical channel identified by its unique port number. 3.To translate software from one computer system to another.

Portal - Web sites that serve as starting points to other destinations or activities on the Web. Initially thought of as a "home base" type of Web page, portals attempt to provide "all of your Internet needs in one location."

Posting - Like posting a message on a bulletin board, the sending of a message to a discussion group or other public message area on the Internet. The message itself is called a "post."

Protocol - The agreed-on rules that computers rely on to talk among themselves. A set of signals that mean “didn’t get it, please resend,” “go ahead,” “all done,” “got it,” and so on. A set of rules that regulate the way data is transmitted between computers.

Provider - In online terms commonly refers to the business or individual who you use to dial-up and access the Internet.

Proxy Server - A server that sits between a client application, such as a Web browser, and a real server. It intercepts all requests to the real server to see if it can fulfill the requests itself.

Public Domain - Computer software on which no copyright exists (usually by a specific statement to that effect by the author), and which may be freely used and distributed.

Pull Down Menu Bar - A bar at the top of the document window which has 'pull-down' menus and allows you to open, print, and save pages, set preferences, search for specific words or phrases, and much more.