P3P - (See "Platform for Privacy Preferences")

packet - A unit of data formatted for transmission on a network. Data are broken up into packets for sending over a packet switching network. Each packet has a header containing its source and destination, a block of data content, and an error-checking code.All the data packets related to a message may not take the same route to get to their destination; they are reassembled once they have arrived.

page fault - An interrupt that occurs when a program requests data that is not currently in virtual memory. The interrupt triggers the operating system to fetch the data from a storage device and load it into RAM. An invalid page fault or page fault error occurs when the operating system cannot find the data at all. This usually happens when the virtual memory area, or the table that maps virtual addresses to real addresses, becomes corrupt.

palmtop - pocket computer.

parallel port - Port (usually 25-pin female) on the computer which supports synchronous, high-speed flow of data along parallel lines to peripheral devices, especially printers.

parity - Error detection method used in both communications and computer memory checking to determine character validity.

partition - A logical section of a disk. Each partition normally has its own file system.

passive-matrix display - A type of liquid crystal display (LCD) which is sometimes used in portable computers. Instead of a transistor for each pixel as in active matrix display, a passive matrix display uses a series of criss-crossed wires having an LCD element at each place the wires intersect.

password - A secret sequence of letters and other symbols needed to log in to a computer system as an authorized user. When a user enters a password, it appears as a line of asterisks ******* so no one can read it.

path - The specification of a directory in a hierarchical file system. The path is usually specified by listing the nodes top-down, separating the directories by the pathname separator (i.e., a backslash, "\"). Also, the list of directories the command interpreter searches for executables.

PCI {pee-cee-eye} [Peripheral Component Interface] - A self-configuring personal computer local bus designed by Intel and supported by most major manufacturers.

PCMCIA {pee-cee-em-cee-ey-ay} [Personal Computer Memory Card International Association] - Consortium of computer manufacturers that devised the standard for the credit-card size adapter cards used in notebook computers.

PCT [Private Communications Technology] - A protocol from that provides secure transactions over the World Wide Web.

peer-to-peer network - A communications network in which any computer on the network can be a client and/or a server. Any computer can access files on any other computer in the network. (compare "client/server")

peripheral - Any part of a computer other than the CPU or working memory, i.e. disks, keyboards, monitors, mice, printers, scanners, microphones, speakers, etc.

personal digital assistant [(PDA] - A pocket-sized personal computer that can store phone numbers, appointments, and to-do lists. Some PDAs have a small keyboard, others have only a special pen that is used for input and output. A PDA can also have a wireless fax modem. Files can be created on a PDA that are later entered into a larger computer.

phishing - {fishing} - a form of online fraud. In a typical phishing fraud, an e-mail - supposedly from a legitimate company or financial institution, asks you to "verify" or "resubmit" confidential information. It may gather this information by asking you to complete an online form or by return e-mail.

PictBridge - A universal direct-print standard adopted by most digital camera manufacturers. It allows digital camera users to connect directly to printers, which have this feature, to print without the use of a computer.

ping {peeng} [Packet Internet Groper] - A program used to test whether a particular network destination is online, by sending an Internet control message protocol (ICMP) echo request and waiting for a response.

pixel [picture element] - the smallest un-breakable unit of a picture on the monitor's screen.

pixelated (or pixellated) - Visible as a pattern of pixels. A bitmapped image can be made of tiny squares which are not individually distinguished by the eye. When the image is enlarged, the pattern of squares is more obvious.

Platform for Privacy Preferences (P3P) - standard published by the World Wide Web Consortium (W3C) designed to help users to gain more control over the use of personal information by Web sites they visit.

plug and play [PnP] - The ability of a computer to automatically detect and configure new hardware components when they are plugged in, without requiring the user to go through complicated installation procedures.

plug and pray - What you do when you're hoping plug and play will work.

plug-in - type of helper application that adds new capabilities to your browser, such as the ability to play audio or video clips. Unlike other kinds of helper applications, a plug-in application installs itself into the Plugins directory within the main browser installation directory and typically can be opened within the browser itself (internally). For example, an audio plug-in lets you listen to audio files on a Web page or in an e-mail message. Macromedia Flash Player and Java are both examples of plug-in applications.

Point of Presence [POP] - a city or location where a network can be connected, often with dial up phone lines.

POP {pop} (See "Point of Presence")

POP {pop} (See "Post Office Protocol")

POP3 [Post Office Protocol 3] - Popular method used for storing Internet mail.

POST {post} [Power-On Self Test] - Short diagnostic routine run by a pc when power is applied, which tests the power supply, CPU, memory, video, drives and other internal components.

posting - A single message entered into a network communications system, such as a newsgroup.

Post Office Protocol [POP] - standard mail server protocol that requires you to download new messages to your local computer - although you can choose to leave copies on the server. With POP, you can store all your messages, including sent mail, drafts, and custom folders, on one computer only. By contrast, IMAP allows you to permanently store all your messages and any changes to them on the server, where you can access them from any computer. Most ISPs currently support POP.

power down - To turn off a computer following the normal procedure, closing any open applications programs before turning off the power. This is the safe way to shut down the computer, and avoids loss of data.

power supply - Electrical component of a computer which converts standard alternating current to the low voltage direct current used by the computer.

PPP [Point to Point Protocol] - Most well known as a protocol that allows a computer to use a regular telephone line and a modem to make TCP/IP connections and be on the Internet.

private key encryption - A form of cryptography in which sender and receiver have the same key or similar keys.

printer - A peripheral device for producing text and images on paper. They include dot matrix, inkjet, led and laser printers.

printer port - A connector found on personal computers intended for attaching a printer.

private key - One of a pair of keys used in public-key cryptography. The private key is kept secret and is used to decrypt data that has been encrypted with the corresponding public key.

processor - central processing unit (CPU).

prompt - Message from the computer that asks the operator to do something, such as enter a command, enter data, etc.

proprietary - In the language of hackers and users, inferior; implies a product not conforming to open-systems standards, and thus one that puts the customer at the mercy of a vendor who can inflate service and upgrade charges after the initial sale has locked in the customer.

protocol - A system of rules and procedures governing communications between two devices. File transfer protocols in your communications program refer to a set of rules governing how error checking will be performed on blocks of data.

proxy - intermediary or "go-between" program that acts as both a server and a client for the purpose of making requests on behalf of other clients.

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. If not, it forwards the request to the real server.

public key - One of a pair of keys used in public-key cryptography. The public key is distributed freely and published as part of a certificate. It is typically used to encrypt data sent to the public key's owner, who then decrypts the data with the corresponding private key.

public-key cryptography - set of well-established techniques and standards that allow an entity (such as a person, an organization, or hardware such as a router) to verify its identity electronically or to sign and encrypt electronic data. Two keys are involved: a public key and a private key. The public key is published as part of a certificate, which associates that key with a particular identity. The corresponding private key is kept secret. Data encrypted with the public key can be decrypted only with the private key.