Technology glossary

Prime Editing

Prime editing is a gene-editing method that can install targeted DNA substitutions, small insertions, and small deletions without requiring a double-strand break or a separate donor DNA template. It uses a modified Cas9 protein linked to a reverse transcriptase and a specialized guide RNA that both targets the site and carries the intended edit.

Privilege Escalation

Privilege escalation is the process of gaining permissions beyond those initially granted, allowing an attacker or compromised process to access protected resources or perform administrative actions.

Pro-Terror Material

Online material that promotes, praises, instructs, recruits for or otherwise supports terrorist acts or organizations, as defined by the applicable law or platform standard. The exact legal scope varies by jurisdiction.

Proactive SIM

A SIM capability defined by cellular standards that allows the card to request selected actions from a phone or modem, such as displaying information, opening a service or executing supported commands.

Programmable Logic Controller(PLC)

A rugged industrial computer that reads sensor inputs and sends programmed commands to machines and other physical equipment.

Programmed cell death

Programmed cell death is a regulated process by which cells activate molecular pathways that lead to their controlled elimination. During development it helps shape tissues, remove excess or damaged cells and refine neural circuits. Apoptosis is the best-known form, but it is not the only regulated cell-death pathway. Detecting fewer cells over time does not by itself identify which pathway was responsible.

Prompt Injection

An attack or failure mode in which untrusted text influences an AI system to follow hidden or conflicting instructions, potentially causing unintended tool use or data disclosure.

Proof Assistant

Software, such as Lean, that helps people write mathematical statements in a formal language and mechanically checks the validity of each inference.

Protected Leave

Time away from work that an eligible employee may take under law or binding policy while retaining specified protections, such as job restoration, continued benefits, or protection from retaliation. Eligibility, pay, duration, and notice requirements vary by jurisdiction and leave type.

Protein aggregation

The association of protein molecules into larger assemblies. Aggregates can differ in size, structure and biological effect; some form ordered amyloid fibrils. Observing or reducing aggregation in a laboratory model does not by itself establish an effect on disease in people.

Protein Reconstruction

The inference of a protein's likely sequence or structure from incomplete, damaged, or indirect evidence.

Proteomic Aging Clock

A computational model that estimates biological age or age-related risk from the concentrations of many proteins in blood or another biological sample. Different clocks may be trained to predict chronological age, mortality, or organ-specific outcomes, so their scores are not interchangeable and do not directly measure lifespan.

Proxy Network

A set of systems that receives network traffic and forwards it to another destination, placing one or more relay points between the original sender and the final service.

Pseudo-direct semiconductor

A pseudo-direct semiconductor has a strong direct optical transition located only slightly above a lower-energy indirect transition. It can absorb light efficiently through the direct transition while charge carriers spend part of their lifetime in the nearby indirect states, slowing radiative electron-hole recombination. The useful balance depends on the energy spacing, temperature, mobility and defect properties.

Pseudolite

A pseudolite is a ground-based transmitter that broadcasts navigation-like ranging signals, acting as a local analogue of a navigation satellite. Pseudolites can augment satellite positioning in controlled areas or where satellite visibility is limited.

Pseudorange

A pseudorange is the apparent distance between a GNSS satellite and receiver calculated from signal travel time. It is called 'pseudo' because receiver clock error and atmospheric effects are initially mixed into the measurement and must be solved or corrected.

Psychedelic-Assisted Therapy

A structured clinical approach in which a psychedelic substance is administered under professional supervision as part of a broader program that includes preparation, monitoring, and psychological support. Evidence, approval status, risks, and legal availability vary by substance and jurisdiction.

Public Interest Journalism

Reporting that helps the public understand matters affecting communities, government, safety, rights and democratic accountability.

Purifying selection

Purifying selection is the removal or reduced persistence of genetic changes that impair biological function. It is usually discussed across generations in populations, but a similar principle can operate among cells within one body when less functional cells fail to survive or reproduce. Evidence of fewer disruptive variants at a later stage can suggest purifying selection, although the underlying mechanism must be tested.

Purpose-Built Autonomous Vehicle

A road vehicle designed from the outset for automated operation rather than adapted from a conventional driver-controlled model.

Pyrocumulonimbus Cloud(pyroCb)

A thunderstorm cloud generated by intense heat and rising air from a wildfire or volcanic eruption. It can produce lightning, strong winds and inject smoke high into the atmosphere.

Quadruple Patterning

A semiconductor fabrication technique that divides one dense circuit pattern across repeated lithography and processing steps. It can create features closer together than a single exposure allows, but adds alignment, defect and cost challenges.

Quantum Chromodynamics (QCD)

The physical theory that describes the strong nuclear force and how quarks and gluons interact to form protons, neutrons, and other particles.

Quantum Network

A network that distributes quantum states or entanglement between separated devices. It may support quantum communication, sensing or distributed computing, but requires specialized sources, channels, memories and detectors.

Quantum-Dot Light-Emitting Diode(QLED)

A light-emitting device that uses semiconductor nanocrystals called quantum dots to produce color when electrically or optically excited. Quantum dots can provide narrow, tunable emission spectra, supporting bright and color-accurate displays and lighting.

Quark

An elementary particle and a fundamental building block of matter; protons and neutrons are each made of three quarks bound together by gluons.

Quasar

An extremely luminous active galactic nucleus powered by matter falling onto a supermassive black hole. Quasars can outshine their host galaxies and are visible across vast cosmic distances, making them valuable probes of the early universe and intervening matter.

Quasi-Solid Electrolyte

An electrolyte with a largely solid or gel-like structure that still permits ions to move between battery electrodes. It aims to combine the conductivity and interfacial contact of liquids with improved leakage resistance, mechanical stability, or safety associated with solids.

Radial Glia

Neural progenitor cells that help organize the developing brain and produce many neurons and glial cells. Their elongated fibers also guide newly formed neurons toward their destinations.

Radiation-Hardened Computing

Computing systems engineered to continue operating in environments with ionizing radiation, such as space or nuclear facilities. Protection may combine specialized components, shielding, redundant circuits, and software that detects or corrects radiation-induced errors.