Technology Glossary

Haptic Feedback

Information communicated to a user through the sense of touch, using forces, vibrations, motion, or changes in surface texture. It can confirm an action, simulate contact, or convey physical properties in phones, vehicles, robots, medical devices, and virtual environments.

Hard Coral Cover

The percentage of a surveyed seafloor area occupied by living reef-building corals with calcium carbonate skeletons. It is a widely used indicator of reef condition, but it does not capture species composition, fish abundance or structural complexity.

Hardware Abstraction Layer

A software layer that provides a common interface while hiding differences between underlying hardware systems.

Hazard Ratio(HR)

A statistic comparing how quickly an event such as death or disease progression occurs over time in two groups. A value below 1 indicates a lower event rate in the treatment group during follow-up.

Heart Rate Variability(HRV)

The variation in time between successive heartbeats. It reflects influences from the autonomic nervous system and is used in research and sports monitoring, but readings depend on measurement quality, activity, illness and individual context.

Heat Load

The amount of heat introduced into a cooled system that the refrigeration stage must remove.

Heat Shock Factor 1 (HSF1)

A protein cells normally produce in response to heat or physical stress, which some cancer cells co-opt to adjust their internal chemistry and match the surrounding tumor conditions.

High-Performance Computing(HPC)

The coordinated use of powerful processors, fast networks and storage to solve computational problems too large or slow for an ordinary computer.

High-Risk AI System

An AI system used in a context where failure or misuse could seriously affect safety or fundamental rights, as defined by applicable regulation. Such systems may face stricter requirements for risk management, data, documentation, oversight, accuracy and security.

Host Factor

A molecule produced by a host cell that a pathogen uses to enter, replicate, or spread.

Hot Isostatic Pressing(HIP)

A manufacturing process that applies high temperature and uniform gas pressure to densify powders or remove internal pores from metal components.

Human-AI Co-Design

A design process in which people and AI systems iteratively contribute ideas, alternatives, evaluations, or refinements. Humans retain responsibility for goals, constraints, context, and final decisions, while AI can expand exploration or automate parts of the workflow.

Human-in-the-Loop AI

An artificial intelligence workflow in which people review, guide, label, approve, or correct parts of a model's operation. Human involvement is often used to improve training data, handle uncertain cases, and provide oversight for consequential decisions.

Human-in-the-Loop System(HITL)

An automated system that requires a person to review, approve or override important outputs before they become final actions.

Human-Machine Interface(HMI)

A human-machine interface is the set of controls, displays, and feedback channels through which a person monitors and operates a machine or industrial system.

Human-on-the-Loop

A supervision model in which an autonomous system, such as an AI flight-control agent, performs a task while a human can monitor it and intervene or take back control at any moment.

Humanoid Robot

A robot with a body plan resembling a person, usually including a torso, head, arms and two legs. The form is intended to help the machine use spaces and tools designed for people, but human-like appearance does not imply human-level intelligence or dexterity.

Hybrid Quantum-Classical Computing

A computing model in which a quantum processor handles selected subproblems while conventional CPUs or GPUs manage data preparation, control and the rest of the workload. The useful division of work depends on algorithms and measured system performance.

Hydrogel

A water-rich polymer network used in biomedical materials, sensors and tissue models.

Hydrogel Actuator

A soft device made from a water-rich polymer network that changes shape or generates force when stimulated by light, heat, electricity, acidity or another input.

Hydrogen Fuel Cell

A device that generates electricity by combining hydrogen and oxygen through an electrochemical reaction, producing only water and heat as byproducts, rather than by burning fuel.

Hyperglycemia

A higher-than-normal level of glucose in the blood, common in uncontrolled diabetes and prediabetes, linked to a range of health risks including some cancers.

Hyperscale Data Center

A very large computing facility designed to scale rapidly across vast numbers of servers, storage systems, and network devices. It typically uses standardized, automated infrastructure to support cloud platforms, internet services, or AI workloads, with substantial power, cooling, water, and land requirements.

Ice-Supersaturated Region(ISSR)

A cold atmospheric region where humidity relative to ice exceeds saturation, allowing ice crystals and persistent contrails to survive and grow. Contrail-avoidance systems try to forecast and route aircraft around these moving zones.

Idiopathic Pulmonary Fibrosis(IPF)

A chronic disease in which lung tissue becomes progressively scarred for no known cause, making breathing and oxygen transfer increasingly difficult. Treatments can slow decline for some patients, but they do not reliably reverse established scarring.

Immune Checkpoint Inhibitor

A cancer therapy that blocks inhibitory signals used by tumors to suppress immune attack.

Immune Checkpoint Therapy

A form of cancer immunotherapy that blocks inhibitory signals, such as PD-1, PD-L1, or CTLA-4, that can restrain T cells. Releasing these checkpoints may help the immune system attack tumors, but it can also cause inflammatory side effects in healthy organs.

Technology glossary