242 results

Pac-Man  First introduced in Japan as Puck-Man May 22, 1980. Released in the United States October 10, 1980.  This Day in Tech History         

package Software available from a Package Management System (PMS).   Wikipedia  Ubuntu Community       

Package Management System (PMS) Manages the software packages on a computer, typically UNIX-like.   Wikipedia         

packet Data at OSI Layer 3.    Wikipedia         

packet buffer             

packet capture (PCAP)    Wikipedia         

Packet Filter (PF)    Wikipedia         

packet filtering firewall Filters layer 3 and layer 4.   SearchNetworking         

packet length    Wikipedia         

packet monkey Derogatory term referring to people who copy code from knowledgeable programmers instead of creating the code themselves.            

packet sniffer Monitors packets through the network.            

Packet-Switched Network Files are split into many pieces before transmitting and may traverse multiple paths to reach the destination. Frame Relay and ATM are examples of a packet-switched WAN.   Wikipedia         

packets per second (pps) Measurement of throughput.   Wikipedia         

paging Form of memory management where main memory retrieves data form another source such as a hard drive.   Wikipedia         

Panther (Mac OS X 10.3)   Wikipedia         


(h,k) vertex
a > 0 minimum
a < 0 maximum
   Wolfram MathWorld  Wikipedia       

parallel Can send multiple bits of information over multiple wires at the same time to theoretically reach the destination faster.   Wikipedia         

Parallel ATA (PATA) Legacy type of storage connector.   Wikipedia         

Parallel Random-Access Memory (PRAM)    Wikipedia         

Paralyze When actual damage is done to the system.            

parameter query Prompst for input every time it runs.   Microsoft Office Training         

Parameter Random-Access Memory (PRAM) A section of non-volatile memory found in Apple computers that stores system settings. May need to be reset by "zapping" the PRAM with the keys Command, Option, P, and R during startup.   Apple Support  TechTerms.com       

parent Directories just above the curent directory.            

parenthesis ( )   Wikipedia         

parity Indicates whether a number is even or odd.   Wikipedia         

parity bit    Wikipedia         

parity file    Wikipedia         

parity flag    Wikipedia         

Partial Attribute Set (PAS)             

partial mesh Network topology that balances redundancy with easy management and cost effectiveness.            

partition Logical division of a physical disk.   Wikipedia         

Pascal Programming language.   Wikipedia         

Pascal GPU microarchitecture from NVIDIA. Named after Blaise Pascal. First introduced April 2016 with the GP100 chip.  Wikipedia         

passive interface Interface that is not receiving updates but can send them. Configured with 'passive-interface' and disabled with 'no passive-interface'.            

passwd Command to change a password in Linux.            


Password Authentication Protocol (PAP)    Wikipedia  RFC 1334       

password recovery

  • //Switch
  • switch: flash_init
  • switch: load_helper
  • switch: dir flash:
  • switch: rename flash:config.text flash:config.text.old
  • switch: boot
   Cisco (Password Recovery Procedures)  Cisco (Catalyst 2960 and 2960-S Software Configuration Guide, 12.2(53)SE1 - Troubleshooting)       

pastebin Web application where users can store plain text.   Wikipedia         

Pastebin.com Pastebin website. Launched September 3, 2002.  Website  Wikipedia       

patch panel    Wikipedia         

PATH Environment variable that displays or sets a search path for executable files.   Wikipedia  LINFO       

path cost The sum of all port costs analog the path to the root bridge. Can be changed with the spanning-tree cost 1-200,000,000 command.            

Pattern-based detection             

Paul Allen Co-founder of Microsoft along with Bill Gates.   Wikipedia         

PAUSE DOS command that suspends processing of a batch file and displays a message.            

payload Contains the Layer 4 segment information and the actual data.            

PC/104 Embedded computer standards which define both form factors and computer buses. PC/104 is intended for specialized environments where a small, rugged computer system is required. The standard is modular, and allows consumers to stack together boards from a variety of COTS manufacturers to produce a customized embedded system. Originally devised by Ampro in 1987 (led by CTO Rick Lehrbaum), and later standardized by the PC/104 Consortium in 1992.  Wikipedia         

pcAnywhere Suite of computer programs by Symantec for remote access. Operates on ports 65301, 22, 5631, and 5632. Originally developed by Dynamic Microprocessor Associates in 1986.  Wikipedia         

PCI Express 4.0  Officially announced June 8, 2017. First devices expected to be released by the end of 2017.  Wikipedia         

PCI Express 5.0  PCI-SIG officially announced the release of the final PCI-Express 5.0 specification May 29, 2019  Wikipedia         

PCI Express Mini Card (Mini PCIe) 52-pin card designed to replace Mini PCI cards. Full-sized cards are 30 × 50.95 mm (width × length) while a Half Mini Card (HMC) are 30 x 26.8 mm.   Wikipedia         

PDP-1  Ran the first game on a minicomputer, Spacewar.  Wikipedia         

PDP-11  Ran the first version of UNIX.  Wikipedia         

PDP-7  Used by Ken Thompson to write UNIX in 1969.  Wikipedia         

peak Maximum amount of voltage attained by a waveform.            

peak-to-peak Amount of voltage measured from the positive-most to the negative-most peak.            

Peer-to-Peer (P2P) Type of network connection. Peers share information without the need of a central server. All devices are technically servers.   Wikipedia         

Penetrate Malicious code is sent to the host.             

penetration test (pen test) Authorized simulated attack on a computer system, performed to evaluate the security of the system.   Wikipedia         

Penryn Microarchitecture codename from Intel. First released November 2007.  Wikipedia         

Pentium II Xeon (Drake) First processor in the Xeon lineup. Announced June 29, 1998.  Wikipedia  Tom's Hardware       

pentode  Invented by Gilles Holst and Bernhard D.H. Tellegen in 1926.  Wikipedia         

Per VLAN Spanning Tree (PVST)    Wikipedia         

Perfect Forward Secrecy (PFS) Property that states that keys used to protect data are not used to derive any other keys. If one key is compromised, all other key should remain secure.    Wikipedia         

performance counters    YouTube         

Performance Optimization With Enhanced RISC - Performance Computing (PowerPC) Microprocessor designed by Apple, IBM, and Motorola (AIM). Released in 1992.  Wikipedia         

perimeter Total distance around the outside edges of the figure.            

Peripheral Component Interconnect (PCI) Expansion card slot found on a motherboard. Created by Intel June 22, 1992.  Wikipedia         

Peripheral Component Interconnect Express (PCIe) (aka: PCI Express) Serial communication with unidirectional serial lanes. Does not slow down when slower devices are connected. Replaced PCI, PCI-X, and AGP. Developed in 2004.  Wikipedia         

Peripheral Component Interconnect eXtended (PCI-X) (aka: PCI eXtended) Based on PCI. Designed for servers. Higher bandwidth and four times faster clock speed than PCI. 1064 MB/s throughput. Parallel communication. Developed in 1998.  Wikipedia         

Perl High level programming language. Originally developed by Larry Wall. First released December 18, 1987.  Website  Wikipedia       

Perl Shell (PSH)             

Permanent Virtual Circuit (PVC) (aka: Private Virtual Circuit). Used to carry both voice and data traffic. Preconfigured by the carrier and only operate in DATA TRANSFER and IDLE modes. Supports data rates up to 4Mbps. More common than SVCs.   Wikipedia    Netacad     

Persist Ensures the malicious code is running even after reboot. May need to change system files to achieve this.            

Personal Computer Memory Card International Association (PCMCIA) Published and maintained a sequence of standards for parallel communication peripheral interfaces in laptops, notably the PC Card (PCMCIA card), and the ExpressCard, all of which are technologically obsolete. Founded September 1989. Dissolved in 2009. Activities now managed by the USB Implementer's Forum.  Wikipedia         

Personal Information Number (PIN) Form of authentication.            

Personal VM Form of VM with RDS.            

Pester    Website  Wikipedia       

petabyte (PB) 1000 terabytes.            

Petya (aka: NotPetya, GoldenEye) Malware. Seen as early as March 2016. Major attack targeting Ukraine occurred June 27, 2017.  Wikipedia         

pfSnese Open source firewall based on FreeBSD.   Wikipedia  Website       

Phase-Shift Keying (PSK) Digital modulation scheme.   Wikipedia         

Phil Spencer Head of Microsoft's Xbox division. Took the roll March 31, 2014.  Wikipedia  Time       

Phil Zimmermann Created of PGP.   Website         

phone freaking (phreaking) Faking the tones for long distance calls on an analog telephone network. Began in the United States during the 1950s.  Wikipedia  Netacad       

PHP 7.0.0  Released December 3, 2015.  PHP News Archive  Wikipedia       

PHP 7.2.2  Released January 31, 2018.  PHP News Archive  Wikipedia       

PHP Data Objects (PDO) Connects to a MySQL database using PHP.   Wikipedia  PHP Manual  PHP Manual  W3Schools  YouTube (Codecourse) 

PHP Hypertext Preprocessor (PHP) Server-side scripting language designed for web development but also used as a general-purpose programming language. The basic syntax looks like this: < ? php //code goes here ?> Originaly released as "Personal Home Page Tools (PHP Tools)" June 8, 1995.  Wikipedia  Website  YouTube (Derek Banas)     

phpMyAdmin Interface for managing MySQL databases through a web browser. First released September 9, 1998.  Wikipedia         

physical address (aka: Layer 2 address or MAC address) Used to identify devices at the physical layer (Layer 2). Allows devices to communicate on the same local network.   Wikipedia         

Physical Address Extension (PAE) Memory management feature for the x86 architecture. Defines a page table hierarchy of three levels (instead of two), with table entries of 64 bits each instead of 32, allowing these CPUs to directly access a physical address space larger than 4 gigabytes. First introduced by Intel in the Pentium Pro, and later by AMD in the Athlon processor.  Wikipedia  Ask Ubuntu       

physical controls e.g. fences, doors, locks and fire extinguishers.   Wikipedia         

Physical Layer (OSI Layer 1) The first and lowest layer. Transmits raw bits from one computer to another and regulates the transmission stream over a medium. This layer may be implemented by a PHY chip.   Wikipedia         

Physical-to-Virtual (P2V) Migrating a physical server to a virtual machine.   Wikipedia         

PhysX Open-source realtime physics engine middleware SDK developed by Nvidia as a part of Nvidia GameWorks software suite.  Acquired from Ageia on February 13, 2008.  Website  Wikipedia       

piconet Ad hoc network that links a wireless user group (WUG) of devices using Bluetooth technology protocols. Consists of two or more devices occupying the same physical channel. Allows one master device to interconnect with up to seven active slave devices.   Wikipedia         

Piledriver Microarchitecture from AMD. Released May 15, 2012.  Wikipedia         

Pin Grid Array (PGA) Type of integrated circuit package, often mounted on printed circuit boards using the through hole method or inserted into a socket.   Wikipedia         

Pine composer (Pico) Text editor for UNIX based systems.   Wikipedia         

ping Network utility used to test network connectivity between devices. Can also be used to test DNS. Example: ping www.google.com Written by Mike Muuss in December 1983.  Wikipedia         

ping sweeps    Wikipedia         

pip Python package manager used to install and remove packages written in python.   Wikipedia         

pipe | (pipe character) Can indicate an option.   Wikipedia         

Pixel Smartphone designed by Google and manufactured by HTC. Released October 20, 2016.  Website  Wikipedia       

Plain Old Telephone Service (POTS)             

plaintext (cleartext)            

plaintext password y u use dis?!?            

plane figure Figure that lies on a plane without thickness.            

Platform as a Service (PaaS) Allows a developer to quickly get software running on the internet without needing to worry about hosting it. Heroku is an example PaaS.   Wikipedia  Netacad       

Platform Controller Hub (PCH)    Website  Wikipedia       


Plex Manufacturing Cloud    Website  Wikipedia       

plug-and-play    Wikipedia         

point-slope form y - y1 = m(x - x1)   Khan Academy         

Point-to-Multipoint (P2MP or PTMP)    Wikipedia         

Point-to-Point Frame    Wikipedia         

Point-to-point network Two routers connected over a common link.   Wikipedia         

Point-to-Point protocol Data link layer protocol. Establishes logical connection (sessions) between two nodes (interfaces).            

Point-to-Point Protocol (PPP) Common non-proprietary Layer 2 protocol found on dedicated leased lines. Sends packets over point-to-point links. Offers features such as: multilink interface, looped link detection, error detection, and authentication. Supports PAP and CHAP authentication. Can be configured on interfaces with asynchronous serial, synchronous serial, HSSI, and ISDN. Defined in RFC 1661 July 1994.  Wikipedia  RFC 1661       

Point-to-Point Protocol over Ethernet (PPPoE) Encapsulating protocol for PPP. Typically used with DSL.   Wikipedia         

Point-to-Point Tunneling Protocol (PPTP) (TCP port 1723) Type of VPN protocol that uses PPP for the tunnel. No real form of authentication, just a password. Only very basic encryption. Oldest VPN protocol.  Wikipedia         

pointer record (PTR) Type of DNS record that maps an IP address to a hostname. Defined in RFC 1035 November 1987.  Wikipedia  RFC 1035       

poison reverse    Wikipedia         

poisonous packet A type of DoS attack. An improperly formatted packet that causes the destination device to slow down or crash.            

Pokémon Go Mobile augmented-reality game for iOS and Android. Released July 6, 2016.  Wikipedia         

polarity dots Schematic symbol used to indicate polarity.            

Policy-based detection             

Polyalphabetic cipher Any cipher based on substitution including The Vigen   Wikipedia         

polyalphabetic key shift             


   Polycom Support (Provisioning Server)         

Pong Video game. Released November 29, 1972.  Wikipedia         

Pooled VM Form of VM with RDS.            

popd Restores the previous value of the current directory saved by PUSHD.   Wikipedia         

port Identifies which application data will go to. 0-1023 are well known ports, 1024-49151 are registered ports, 49152-65535 are private and/or dynamic ports. Several ports include:

Well Known Ports
port 0 (Legacy) 768 bit key.
port 21 FTP
port 22 SSH
port 23 Telnet
port 25 SMTP
port 53 DNS
port 80 HTTP
port 110 POP3
port 143 IMAP
port 161 SNMP
port 194 IRC
port 443 HTTPS
port 520 RIP
port 531 Chat (AOL Instant Messenger)
Registered Ports
port 1433 MS SQL
port 1812 RADIUS authentication protocol.
port 1863 MSN Messenger, TCP
port 2000 Cisco SCCP (VoIP), TCP
port 2948 WAP (MMS)
port 5004 (RTP) Voice and video transport protocol.
port 5060 SIP (VoIP)
port 8008 Alternate HTTP
   IANA  Wikipedia (Port 0)       

port 465 (SMTPS)   Wikipedia  Stack Overflow       

Port Address Translation (PAT) Many-to-one address mapping. An extension of NAT also known as NAT overload.   YouTube         

Port Aggregation Protocol (PAgP) Cisco proprietary protocol for EtherChannel. Modes: On - forces the interface to channel without PAgP. PAgP desirable - interface in active negotiating state. PAgP auto - interface in passive negotiating state            

port mapping             

port scan Method of finding out which services a host computer offers.   Wikipedia         

Port Security Prevents MAC address spoofing and MAC table overflows. Can statically assign or dynamically learn MAC addresses to permit.   Cisco         

Portable Network Graphics (PNG) Designed for transferring images on the Internet, not for professional-quality print graphics.   Wikipedia         

Portable Operating System Interface (POSIX) IEEE standard for software compatibility with various UNIX-based operating systems. Standardized by Richard Stallman and IEEE in 1988.  Wikipedia         


positional parameters             

POST POST and PUT are used to upload data files to the web server. When a user submits data in a form the POST message is sent along with the data.            

Post Office Protocol (POP) (v2, port 109. v3, port 110.) Application layer protocol used for receiving email. First defined in RFC 918 October 1984.  Wikipedia  RFC 918       

Post Office Protocol version 2 (POP2)  Defined in RFC 937 February 1985.  Wikipedia  RFC 937       

Post Office Protocol version 3 (POP3)  Defined in RFC 1081 November 1988.  Wikipedia  RFC 1081       

posture assessment             

Potentially Unwanted Program (PUP)             

Power Mac G4  Released August 31, 1999.  Wikipedia         

Power Mac G5  Released June 23, 2003.  Wikipedia         

Power Macintosh 8600 (code name: Kansas) First released February 17, 1997.  Wikipedia         

Power Macintosh G3 (Beige)  Released November 1997.  Wikipedia         

Power Macintosh G3 (Blue & White)  Released January 5, 1999.  Wikipedia         

Power over Ethernet (PoE) (802.3af)            

Power-On Self Test (POST) Test run immediately after a device is powered on.   Wikipedia         

PowerBook 100  Released October 21, 1991.  Wikipedia         

PowerBook 140  Released October 21, 1991.  Wikipedia         

PowerBook 170  Released October 21, 1991.  Wikipedia         

PowerPivot    Microsoft Developer Network         

PowerShell Windows Command Prompt with a more Linux feel. Comes in blue by default. First released November 14, 2006.  Website  Wikipedia  PowerShell.org     

PPP frames

{ Flag | Address | Control | Protocol | Data | Frame Check Sequence (FCS) }

Pre-Shared Keys (PSK) (shared secret) Authentication method used by IPsec   Wikipedia         

Preamble Start of an Ethernet frame.   Wikipedia         

Precision 3510 Workstation laptop from Dell.   Website  Wikipedia  Support     

prefix Number of network bits in the subnet mask. /24=            

preformatted text (pre) pre HTML tag that defines preformatted text, such as computer code.   W3Schools         

Presentation Layer (OSI Layer 6) Translates application layer data to an intermediate form that provides security, encryption, and compression for the data.   Wikipedia         

Pretty Good Privacy (PGP)             

preventive controls (before the event) intended to prevent an incident from occurring e.g. by locking out unauthorized intruders.   Wikipedia         

preventive maintenance The regular and systematic inspection, cleaning, and replacement of worn parts, materials, and systems.   Netacad         

Primary Domain Controller (PDC)             

primary key (aka: unique identifier)            

primitive data type A basic or built-in type.   Wikipedia         

PRINT DOS command that prints a text file.            

Printed Circuit Board (PCB)    Wikipedia         

Printer Command Language (PCL)  First released on the HP ThinkJet 2225 in 1984.  Wikipedia         

Printer Driver Isolation Runs printer drivers in a separate process from the print spooler.   MSDN         

private address Private IPv4 address ranges are: - ( - ( - (
   Wikipedia  RFC 1918       

Private and/or Dynamic Ports 49152-65535            

Private Branch Exchange (PBX)             

private key (aka: symmetric encryption)Anyone can encrypt a message with the receiver’s public key, but it can only be decrypted with the receiver’s private key. Effective security only requires keeping the private key private; the public key can be openly distributed without compromising security. Can be used for nonrepudiation to ensure only the person with the private key could have encrypted the message. Anyone who possesses the public key can then decrypt it.   Wikipedia         

Private Virtual Circuit (PVC) (aka: Permanent Virtual Circuit (PVC)   Wikipedia         

Private VLAN (PVLAN) Edge (protected ports)   Cisco         

private WAN infrastructure Dedicated (Leased Lines) and Switched (Circuit or packet switched) WANs.            

privilege escalation    Wikipedia         

Probe Vulnerable computers are identified. ICMP is used to map the network. Passwords are obtained by social engineering, brute-force attacks, dictionary attacks, or packet sniffing.            

procedural controls e.g. incident response processes, management oversight, security awareness and training.   Wikipedia         

procedural languages (third-generation languages) Examples include BASIC, COBOL, FORTRAN, and C.            

procedural programming Programs are separated into small modules and called by the main program or other module when needed.            

procedure (aka: modules or subprograms) Small sections of program code.            

procedure call locates specific tasks in procedures.            

process    Wikipedia         

Process ID (PID)             

process status (ps) Displays the currently-running processes.   Wikipedia         

program Instructions written for a computer to do a specific task.   Wikipedia         

Program Development Life Cycle (PDLC) (aka: Systems Development Life Cycle (SDLC), Application Development Life Cycle (ADLC))   Wikipedia         

Programmable Logic Controller (PLC) Computer used for automation or controlling industrial machinery.   Wikipedia         

programming The process of making a program.            

Programming Language One (PL/I)             

programming paradigm A style of programming.   Wikipedia         

Project Brillo Android based OS for IoT. Developed by Google.   Website  Ars Technica       

Project Honolulu Web-based server management GUI. Announced September 14, 2017.  Ars Technica         

Project Valerie Triple monitor laptop from Razor. Announced at CES on January 5, 2017  Website  PCMag       

promiscuous mode Where a network adapter is set to captures packets.            

PROMPT Changes the Windows Command Prompt.            

Propagate Sending the malicious code to other devices. This could be through email, FTP, IRC, or other ways of file sharing.            

Protected Extensible Authentication Protocol (PEAP) (aka: Protected EAP) Encapsulates the Extensible Authentication Protocol (EAP) within an encrypted and authenticated Transport Layer Security (TLS) tunnel. Uses TLS to authenticate the server to the client but not the client to the server.   Wikipedia  Quizlet       

Protocol Protocols provide the rules and formats that govern how data is treated.            

Protocol Data Unit (PDU) The form that a piece of data takes at any layer.            

protocol field Part of a packet header represented by a number to identify the protcol being used in the PDU. 6 is used to indicate TCP, 17 for UDP, 88 for EIGRP, 89 for OSPF.            

Protocol-Dependent Module (PDM) Allows EIGRP to route for various Layer 3 protocol packets. (IPv4 and IPv6)   Wikipedia         

Provider Edge (PE) MPLS element that is the provider's router connecting the customer.   Wikipedia         

proxy server Acts as an intermediary for requests from clients seeking resources from other servers. May reside on the user's local computer, or at various points between the user's computer.   Wikipedia         

PS/2 Peripheral connection using 6-pin mini-DIN. Designed in 1987.  Wikipedia         


pseudocode Outlines program logic using code that is easy to understand, but not always with the proper syntax.   Wikipedia         

pstree Shows the running processes as a tree in Bash.   Wikipedia         

PSVersionTable ($PSVersionTable) PowerShell variable that contains information regarding the installed PowerShell version.


Psyb0t (aka: Network Bluepill) Computer worm thought to be unique in that it can infect routers and high-speed modems. Discovered in January 2009.  Wikipedia         

public key Used in asymmetric cryptography to encrypt.   Wikipedia         

public key certificate             

Public Key Infrastructure (PKI) Manages digital certificates. Two major parts: certificate and certificate authority.   Wikipedia         

Public Switched Telephone Network (PSTN) A circuit-switched WAN.            

public WAN infrastructure Internet. (Broadband, VPN)            

Pulse-Code Modulation (PCM)    Wikipedia         

Puma (Mac OS X 10.1)   Wikipedia         

Punch card    Wikipedia         

pure inductive circuit Voltage and current are 90° out of phase.            

pure resistive circuit Current and voltage are in phase.            

pushd Saves the current directory then changes it.   Wikipedia         

PUT POST and PUT are used to upload data files to the web server. PUT uploads resources or content to the web server such as an image or file.            

PuTTY Terminal emulator for Windows.   Website         

PVC status

DELETED PVC is not present and no LMI information is being received
INACTIVE Connection to remote host is unavailable
STATIC LMI is disabled on that interface

pwd Command that prints the working directory.            

Pythagorean theorem a2 + b2 = c2   Khan Academy         

Python High-level programming language that uses a simple syntax First released February 20, 1991.  Website  Wikipedia