P

package

A special kind of folder that can have embedded executable instructions. Often used to install application or operating system components, or files that must be placed in specific locations. An application package is called a bundle.

pane

Any region of changeable content within a dialog or window.

path

Route through a file system to a particular item.

partition

Discrete section of a hard disk. Also known as volume.

PC Card

A standard that contains the physical, electrical, and software specifications for an integrated circuit card usually used in portable systems. Also known as PCMCIA.

PCI (Peripheral Component Interconnect)

Bus standard that provides a channel or path between the components in a computer.

PDF (Portable Document Format)

A standard graphics format used for rendering and printing. It was developed by Adobe.

permission

In a multiuser operating system, authorization that provides a measure of security needed to keep one user from modifying or viewing another user's items on the computer. The three permissions are read, write, and execute.

PID (Process identification number)

The number used in multiuser operating systems to uniquely identify running processes.

plug-in

A software module that extends the functionality of an application or framework.

POP (Post Office Protocol)

A networking protocol used to access electronic mail from a mail server. It relies upon user-specific mailboxes that reside on the mail server, and as a result can be much more resource-intensive than IMAP.

POSIX (Portable Operating System Interface for UNIX)

A set of standard operating system interfaces based on the UNIX operating system.

PostScript

A programming language developed by Adobe that describes the appearance of a printed page.

PPP (Point-to-Point Protocol)

A networking protocol used to connect two peer machines using a common solution, such as a modem.

PPPoE (Point-to-Point Protocol over Ethernet)

A networking protocol used to connect two peer machines using a broadband solution, such as a DSL modem.

preemptive multitasking

Method of running multiple processes simultaneously where the operating system can interrupt, or preempt, a currently running task to run another task.

process

A task; a running program or set of threads.

protected memory

Memory scheme in which an operating system allocates a unique memory address space in RAM for each application or process running on the computer, and prevents applications from accessing memory outside of their allocated space.

protocol

Networking language. A special set of rules that relate to intercommunication between systems.