Packet
A transmission unit of fixed maximum size that consists of binary information representing both data and a header containing an ID number, source and destination addresses, and error-control data.

PANOSE
A font matching system based on a numeric classification of fonts according to visual characteristics.

Parse
To analyse or separate (for example, input) into more easily processed components.

Password
A unique string of characters that must be provided before logon or access to a resource or service is authorized.
Password Authentication Protocol (PAP)
A security protocol that uses a two-way handshake for the peer to establish its identity.

Password caching
Automatically storing a password in a password list (PWL) file so that whenever the user logs on again, the logon password unlocks the PWL file and the resource passwords it contains.

PC Card
A trademark of PCMCIA. A removable device that is designed to be plugged into a PC Card slot and used as a memory-related peripheral.

PCI
Peripheral Component Interconnect. A high-performance, 32-bit or 64-bit bus designed to be used with devices that have high bandwidth requirements, such as display subsystems.

PCMCIA
The Personal Computer Memory Card International Association, which standardizes credit card-sized interface cards used in portables and other small computers.

Permission scoping
Preventing permissions granted to a trusted component from being misused, either intentionally or inadvertently, by a less trusted component.

Permission signing
Allowing a signed cabinet file to specify securely not only the identity of the signer but also the set of permissions being requested for the signed classes.

Personal Information Exchange (PFX)
A set of public key-based security technologies that is part of the Microsoft Internet security framework.

Platform for Internet Content Selection (PICS)
A system providing for the voluntary rating of World Wide Web site content by either the publisher of the page or a third-party rating group.

Plug and Play
A design philosophy and set of specifications that describe hardware and software changes to the PC and its peripherals, making it possible to add new components without having to perform technical procedures.

Point-to-Point Tunneling Protocol (PPTP)
Protocol that enables a computer to securely connect to the Internet or an intranet by tunneling through an Internet or LAN connection.

PPP
Point-to-Point Protocol. An industry standard, a part of Windows 98 Dial-Up Networking, designed to ensure interoperability with remote access software from other vendors. It is used in making point-to-point links, especially with dial-up modem servers.

PPTP
See Point-to-Point Tunneling Protocol.

Pre-emptive multitasking
A method by which the operating system takes control away from or gives control to another running task, depending on the needs of the system.

Private Communication Technology (PCT)
A protocol used to create a secure Internet or intranet channel.

Protected mode
An operating mode supporting more advanced features than real mode, including multitasking, data security, and virtual memory.

Protocol
A set of rules and conventions by which two computers pass messages across a network. Networking software usually implements multiple levels of protocols layered one on top of another. Windows 98 includes NetBEUI, TCP/IP, and IPX/SPX-compatible protocols.

Protocol rollover
Sending ASF files over a default protocol and then trying to send them via an alternative server or protocol if the original attempt fails.

Proxy server
A server that acts as a go-between, converting information from Web servers into HTML to be delivered to a client computer. It also provides a way to deliver network services to computers on a secure subnet without those computers needing to have direct access to the World Wide Web.

Pull model
A broadcast model in which information is downloaded as it is requested.

Push model
A broadcast model in which a server sends information to a large number of clients on its own schedule, without waiting for requests. The clients scan the incoming information, save the parts they have been instructed to save, and discard the rest.