Technology glossary

Content Provenance

A record of where a piece of digital content came from and how it changed. Provenance can include the capturing device, creator, editing steps, timestamps and cryptographic credentials, helping people assess authenticity without relying only on visual inspection.

Context Window

The maximum amount of information a language model can consider at one time when processing or generating a response. It typically includes the prompt, conversation history, supplied documents, and generated tokens, and is measured in tokens rather than words.

Continual Learning

A method that lets a model learn from a sequence of new tasks or data while trying to preserve useful knowledge acquired earlier.

Continuing Resolution

A temporary US law that keeps some or all federal agencies funded when regular annual appropriations have not been completed. It usually extends existing funding rates for a limited period and may include special provisions. A continuing resolution prevents an immediate funding lapse but does not replace the final budget decisions Congress still must make.

Contrail Avoidance

An operational strategy that changes an aircraft’s altitude or route to avoid atmospheric zones where strongly warming contrails are likely to form. Its net benefit depends on forecast accuracy, execution rate and any additional fuel burned.

Contrail Cirrus

Thin, high ice cloud that develops when persistent aircraft contrails spread and lose their original linear shape. Its climate effect varies with location and time, but globally it is considered a net source of warming.

Controlled Lunar Impact

A planned end-of-mission trajectory that deliberately sends a spacecraft or rocket stage into a selected area of the Moon. Operators may use it for disposal or science when the time and location can be predicted and documented.

Controlled-NOT Gate(CNOT)

A two-qubit quantum logic gate in which one qubit controls whether another qubit is flipped.

Coordinated Universal Time(UTC)

Coordinated Universal Time (UTC) is the international reference time scale used for civil timekeeping. GNSS systems maintain their own internal time scales and provide information that allows receivers and timing equipment to relate them to UTC.

COPD Exacerbation

A sudden worsening of chronic obstructive pulmonary disease symptoms beyond normal day-to-day variation. Moderate episodes usually require systemic steroids or antibiotics, while severe episodes commonly require emergency care or hospitalization.

Copyright Settlement

A negotiated agreement resolving a copyright dispute without a final trial judgment on every legal issue.

Coral Bleaching

A stress response in which corals lose or expel the microscopic algae living in their tissues, causing the colony to turn pale or white. Bleached coral is still alive at first, but prolonged stress raises the risk of starvation, disease and death.

Core-Shell Nanoparticle

A nanoscale particle built from an inner material surrounded by a distinct outer material. Separating the optical or chemical roles of the core and shell lets researchers tune scattering, stability, surface chemistry and compatibility.

Coronagraph

An optical system that suppresses light from a bright star so that much fainter nearby objects can be observed. It uses masks and carefully controlled optics, but residual starlight still limits which planets can be detected.

Coronal Mass Ejection (CME)

A massive eruption of magnetized plasma from the Sun's outer atmosphere, the corona. When an Earth-directed CME strikes the planet's magnetic field, it can trigger geomagnetic storms that produce auroras but can also disrupt power grids, satellites, and radio and GPS signals.

Correlated Color Temperature(CCT)

A lighting metric expressed in kelvins that describes whether a white or near-white light appears warmer and more amber, or cooler and more blue. It is a useful shorthand, but the full spectrum is needed to predict biological effects.

Cortical Synchronization

Coordinated timing of electrical activity across populations of neurons in the cerebral cortex. Strong slow synchronization is characteristic of deep NREM sleep, although it also appears in other brain states and is not by itself proof of sleep.

Cosmic Redshift

The shift of light from distant astronomical objects toward longer, redder wavelengths, commonly caused by the expansion of the universe stretching the light during its journey. Astronomers use redshift to infer cosmic distance, expansion history, and the epoch from which the light originated.

Cost-Effectiveness Analysis

A method that compares the health outcomes and costs of different medical interventions.

Counterintelligence

The work of detecting, understanding and disrupting intelligence activity conducted by foreign states or other hostile actors. In technology protection it can combine security investigations, insider-risk controls, cyber defence and cooperation with law enforcement, while remaining subject to legal limits and oversight.

Country-of-Origin Claim

A statement indicating where a product was manufactured, assembled or substantially transformed. Legal requirements vary by jurisdiction and by how qualified the wording is, so a marketing phrase may need evidence about components, processing and final assembly.

Covered List

A government list of communications equipment and services considered to pose an unacceptable national-security risk.

Crater Ejecta

Rock, dust and fragmented material thrown outward when an object strikes a planetary surface and excavates a crater. Ejecta can blanket nearby terrain, bury older landforms and make geological mapping more difficult.

Credential Surrogation

A design in which a trusted service uses a password or token on behalf of an application without revealing the original credential to it.

CRISPR(CRISPR)

CRISPR is a natural defense system found in bacteria and archaea that stores short pieces of genetic material from past infections and uses them to recognize matching invaders. Scientists adapted this system into a programmable platform for targeting specific DNA sequences in research, diagnostics, and gene editing.

CRISPR-Cas9(CRISPR-Cas9)

CRISPR-Cas9 is a gene-editing system that combines a programmable guide RNA with the Cas9 enzyme. The guide RNA directs Cas9 to a chosen DNA sequence, where Cas9 cuts the DNA so the cell’s repair machinery can disable a gene or introduce a planned genetic change.

Cross-Border Censorship

The suppression, restriction, or manipulation of information in one country through pressure, legal demands, technical controls, or platform policies that reach across national borders. It may target media, online speech, diaspora communities, or services operating internationally.

Cross-Origin Access

Access by one website or embedded context to data or actions belonging to a different web origin.

Cryogenic Control Electronics

Electronic circuits designed to generate, route or measure control signals while operating at extremely low temperatures near quantum processors. Placing control closer to qubits can reduce wiring, but the circuits must limit heat and electrical noise.

Cryogenic Dark Matter Detector

A detector operated at extremely low temperature to measure tiny energy deposits that could be produced by dark matter interactions.