Technology glossary

Differential GPS(DGPS)

Differential GPS (DGPS) improves positioning accuracy by comparing satellite measurements at a receiver with measurements from a nearby reference station whose location is precisely known, then applying corrections to common errors.

Digital Elevation Model(DEM)

A digital representation of ground-surface elevation used in terrain and flood analysis.

Digital Entitlement

A platform record that confirms an account or device may access specified digital content under defined ownership, subscription, or licensing conditions.

Digital Markets Act(DMA)

A European Union regulation that sets obligations and prohibitions for large digital platforms designated as gatekeepers. It aims to make digital markets fairer and more contestable by addressing practices involving self-preferencing, data use, interoperability, app distribution, and business-user access.

Digital olfaction

Technologies that sense, encode, classify, generate or control odor-related information using electronic systems. Some systems identify an odor category and trigger a prepared fragrance, while more ambitious approaches attempt to reproduce complex odor mixtures.

Digital Platform Levy

A compulsory charge applied to qualifying online platforms, often calculated from local revenue and sometimes reduced through approved commercial agreements.

Digital Twin

A digital representation of a physical object or system that updates using real-world data.

Digital Watermark

A signal embedded in digital media to indicate its source, ownership or processing history. It can be visible or hidden and may help compatible tools identify AI-generated content, but cropping, re-encoding or screen capture can weaken some implementations.

Digital-to-Analog Converter(DAC)

A circuit that converts digital values into analog electrical signals.

Dilution of Precision(DOP)

Dilution of Precision (DOP) describes how satellite geometry amplifies or reduces GNSS measurement errors. Satellites spread widely across the sky generally produce better geometry and a lower DOP than satellites clustered in one direction.

Dilution Refrigerator

A cooling system that uses mixtures of helium isotopes to reach temperatures of a few millikelvin.

Direct bandgap

A direct bandgap is an electronic structure in which an electron can move between the valence and conduction band edges without a substantial change in crystal momentum. This makes light absorption and emission efficient, which is useful in LEDs and thin solar absorbers, but it can also permit faster radiative recombination.

Direct Imaging of Exoplanets

The detection of light coming from an exoplanet as a spatially separate source from its host star. Because starlight is overwhelmingly brighter, the method uses high-contrast optics, coronagraphs, adaptive optics, or interferometry and is best suited to certain large, young, or widely separated planets.

Direct Liquid Cooling

A cooling method that brings liquid close to, or directly across, heat-producing components such as processors and accelerators. Liquid carries heat more effectively than air and can reduce fan and chiller requirements in dense computing systems.

Directed Evolution

An engineering method that repeatedly mutates and selects biological molecules to improve a desired function.

Disc-to-Digital

A system that uses a verified physical game disc to authorize downloading, streaming, or otherwise accessing a digital version while preserving rules tied to the original disc.

Discretionary Grant

Public funding awarded through an agency's judgment rather than paid automatically under a fixed eligibility formula. Applicants usually compete under stated criteria, and the agency selects projects that fit the program's purpose and available budget. The word discretionary describes the decision process, not permission to ignore laws or published rules.

Dissipative Entanglement

Quantum entanglement created or stabilized through carefully engineered interaction between a quantum system and its environment. Instead of treating dissipation only as harmful noise, researchers design it to drive the system toward a desired entangled state.

District Heat Recovery

The capture of otherwise wasted heat from facilities such as data centers and its transfer into a local network that heats buildings or water. Its usefulness depends on temperature, distance, seasonal demand and the energy required to move the heat.

DNA Metabarcoding

A method that identifies many species in a mixed environmental or biological sample by sequencing short diagnostic regions of DNA and comparing them with reference databases.

DNA Origami

A nanotechnology method that folds a long DNA strand into a planned shape using many shorter strands as molecular staples. The resulting structure can position molecules with nanometre precision and can be designed to move, bind targets or carry cargo.

DNA Strand Displacement

A programmable reaction in which one DNA strand binds to a matching exposed region and replaces another strand in a DNA complex. Designers use the sequence of bases to control which reaction happens and when, allowing DNA devices to behave like molecular switches or motors.

DNAzyme

A DNA molecule selected or engineered to catalyse a chemical reaction, rather than merely store genetic information. Many DNAzymes cut a specific RNA sequence when the required metal ions and molecular conditions are present.

Driver Mutation

A genetic change that gives a cell a growth advantage and contributes directly to cancer development.

Droplet Microfluidics

A technique that moves and manipulates tiny droplets through microscopic channels. Each droplet can serve as an isolated reaction vessel, allowing many experiments to run with very small quantities of material.

Drug-Likeness

A set of chemical and physical properties used to estimate whether a molecule could become a practical medicine.

Dual-Frequency GNSS

Dual-frequency GNSS receivers track satellite signals on two radio frequencies. Comparing the two helps correct ionospheric delay and can improve accuracy and robustness compared with single-frequency positioning.

Dual-Use Capability

A technical ability that can support legitimate and harmful goals. In AI security, vulnerability discovery can help defenders find and patch software flaws, but the same capability can help attackers identify targets and automate exploitation. Risk depends on access, tools, operating context and controls, not on the capability alone.

Durability of Response(DoR)

The length of time a clinically meaningful improvement or tumor response persists after it begins. In oncology, duration of response is typically measured from the first documented response until disease progression or death under a predefined study protocol.

Dynamic Balance

The ability of a moving system to manage momentum and recover stability while its centre of mass may temporarily move outside the current support area. Running robots maintain it by sensing body motion and adjusting foot placement and joint forces in real time.