Technology glossary

Attack Surface

All reachable devices, accounts, software and connections that an attacker could potentially use to enter or influence a system.

Auscultation

Listening to the heart or lungs with a stethoscope, digital or acoustic, to detect abnormal sounds like murmurs or irregular rhythms.

Automated Ball-Strike System(ABS)

A pitch-tracking system that compares a baseball's path with a computed strike zone. In challenge mode, a human umpire makes the original call and an eligible player may request an electronic review.

Automated Employment Decision

An employment-related decision or recommendation made or substantially assisted by an automated system, such as screening applicants, ranking candidates, assigning work, evaluating performance, setting pay, or selecting workers for promotion or dismissal. Applicable legal definitions vary by jurisdiction.

Automated Theorem Discovery

The use of computer systems to generate mathematical conjectures, identify patterns, or formulate new theorem candidates, often with symbolic reasoning, search, machine learning, or formal methods. A discovered claim becomes an established theorem only after a valid proof is produced and checked.

Autonomous Cyber Agent

An autonomous cyber agent is an AI-driven system that can plan and perform multi-step cybersecurity tasks, adapt to results, and continue pursuing an objective with limited human direction.

Autonomous Manipulation

A robot's ability to perceive, grasp, move, and interact with objects without continuous human control. It combines sensing, planning, control, and often machine learning to adapt actions to the object and surrounding environment.

Autonomous Underwater Vehicle(AUV)

An untethered robotic vehicle that travels underwater and carries out a programmed or adaptive mission without continuous control from a human operator. It uses onboard navigation, sensors, computing, and propulsion for mapping, inspection, research, or defense tasks.

Avoided Emissions

Greenhouse gas emissions that do not occur because an intervention replaces or reduces a higher-emitting activity relative to a defined baseline. The estimate depends on what would realistically have happened without the intervention.

Background Radiation

Unwanted natural or cosmic radiation that can imitate or obscure the signal sought by a detector.

Bacterial Membrane Vesicle

A small membrane-bound particle released by bacteria that carries proteins, lipids and signaling molecules.

Ballistic Heat Transport

Heat transport in which energy carriers travel over significant distances with little scattering.

Balmer Break

A sharp change in a spectrum near 364.6 nanometres caused by how hydrogen atoms absorb light. Its strength can help astronomers distinguish stellar populations from unusually dense gas around an active source.

Band-to-Band Tunnelling(BTBT)

A quantum process in which charge carriers pass through an energy barrier from one semiconductor band into another instead of going over the barrier. Tunnel transistors use it to switch at lower gate voltage.

Baryon Junction

A theorized Y-shaped configuration of gluons connecting a proton's three quarks, proposed as an alternative carrier of baryon number to the quarks themselves.

Baryon Number

A conserved quantum property that distinguishes ordinary matter particles, such as protons and neutrons, from antimatter, and that stays constant in particle interactions.

Baryonic Matter

Ordinary matter made primarily of protons and neutrons, including stars, gas, planets, and people.

Base Editing

Base editing is a gene-editing technique that can change one DNA letter into another without making a double-strand break in the DNA. It typically combines a modified CRISPR protein with a chemical-modifying enzyme, allowing some single-letter mutations to be corrected more precisely than with conventional DNA cutting.

Baseband Processor

A processor that manages a device's cellular radio communications, including network registration, signal processing, calls, messages and mobile data, usually separately from the main application processor.

Bat Sensor

A motion-sensing device attached to or embedded in a baseball bat to record measurements such as swing speed, angle and path.

BDNF (Brain-Derived Neurotrophic Factor)

A protein that normally helps nerve cells grow and survive, particularly in the brain, but which some tumors co-opt to draw nerves into themselves and fuel their own growth.

Behavior-Based Detection

A security approach that identifies suspicious activity from what programs, users or devices do, such as hidden command execution or unusual network access, rather than relying only on known file signatures.

BeiDou

BeiDou is China's global satellite navigation system, providing positioning, navigation and timing services worldwide. Compatible receivers can combine BeiDou signals with GPS, Galileo and other GNSS constellations.

Benthic Cover

The proportion of the seafloor covered by organisms or materials such as hard coral, soft coral, algae, seagrass, sand or rubble. Scientists estimate it from standardized observations to track how bottom habitats change over time.

Betavoltaic Battery

A device that converts energy from beta radiation directly into electricity over long periods.

Bio-Based Manufacturing

The production of materials, chemicals, fuels, or other goods using renewable biological feedstocks or biological processes. It may use plants, algae, microbes, enzymes, or organic waste and is not automatically sustainable unless its full resource and environmental impacts are assessed.

Biocatalysis

The use of enzymes or cells to accelerate chemical reactions.

Bioelectrical Signal

An electrical voltage or current generated by biological activity in cells, tissues, or organs. Examples include signals measured by electrocardiography, electroencephalography, and electromyography, which can reveal aspects of heart, brain, or muscle function.

Biofilm

A structured community of microorganisms attached to a surface and embedded in a self-produced matrix.

Biohybrid Robot

A robotic system that combines living biological components with engineered electronics, sensors, control or mechanical parts.