Glossary: AI, Power and Data Center Words

Plain words for the machines, electricity and ideas behind AI. Browse by letter or find a word.

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A

AC (alternating current): Electric current that changes direction again and again. Power grids usually deliver electricity this way.
Accelerator: A chip built to speed up a certain kind of computing work, such as AI calculations.
AI (artificial intelligence): Computer programs that learn patterns from lots of examples.
Air cooling: Using moving air to carry heat away from equipment.
All-reduce: A computing step that combines results from several processors and shares the combined result with each one.
Allegation: A claim that still needs evidence to show whether it is true.
Ampere (amp): A unit measuring how much electric charge flows each second.
Anode: The electrode where a reaction releases electrons. In a hydrogen fuel cell, fuel enters this side.
Atom: A tiny building block of matter. Each atom has a center called a nucleus.

B

Backup power: An extra electricity supply that takes over when the main supply fails. Learn more
Bandwidth: How much data a connection can carry in a set time.
Batching: Grouping several computing requests so hardware can work on them together.
Battery: A device that stores energy through chemical changes and supplies electricity later.
Battery storage: A system of batteries and controls that stores energy for later use.
Behind-the-meter: On the customer’s side of the power company’s meter, where electricity use is measured.
Blackout: A loss of electrical power across an area.
Blowdown: Water drained from a cooling system to stop minerals from building up too much.
Bottleneck: A slow or limited part that holds back the whole system, like a narrow doorway slowing a crowd.

C

Capacity: The largest amount a system is designed to handle. Available capacity can differ from what is actually being used.
Capacity factor: The electricity made over time compared with the most it could make running at full power the whole time.
Catalyst: A material that helps a chemical reaction happen without being used up overall.
Cathode: The electrode where a reaction takes in electrons. In a hydrogen fuel cell, oxygen reaches this side.
CDU (coolant distribution unit): Equipment that manages cooling liquid flow and transfers heat between liquid loops in a data center.
Cell: One working unit of a battery or fuel cell. Several cells can be joined together.
Checkpoint: Saved AI training progress that lets a computer continue after an interruption.
Chemical reaction: When substances combine or break apart to make something new.
Chiller: A machine that removes heat from a liquid, often using a refrigeration cycle.
Chip: A small piece of material holding tiny electrical parts that process or store information.
Circuit: A complete path that lets electric charge flow through equipment and return.
Cloud computing: Using computers reached over a network instead of doing all the work on your own device.
Cluster: A group of connected computers working as one system.
CO2 (carbon dioxide): A gas released when carbon-based fuels burn or react. Adding it to the air warms the climate.
Cold plate: A metal part that collects heat from a chip and passes it to cooling liquid.
Combined cycle: A power system that uses a gas turbine’s exhaust heat to make steam and generate more electricity.
Commissioning: Testing and checking newly installed equipment before putting it into regular service.
Compressor: A machine that squeezes a gas, raising its pressure.
Compute: The work computers do to process information and run calculations.
Coolant: A liquid or gas used to carry heat away from equipment.
Cooling loop: A path that cooling liquid follows before returning to its starting point.
Cooling tower: Equipment that releases heat outdoors, often by letting some water evaporate.
Cost allocation: Rules for deciding who pays which share of a shared expense.
CPU (central processing unit): A computer’s main processor. It handles instructions and coordinates many different jobs.
Current: The flow of electric charge through a material or device.
Curtailment: Reducing or stopping electricity use or production when the power system needs it.

D

Data: Information computers store or work with, such as numbers, words, pictures or sounds.
Data center: A building or group of buildings holding computers, storage and the equipment that keeps them running.
DC (direct current): Electric current that flows in one direction. Batteries supply direct current.
Demand: The amount of electrical power people and equipment need at a particular time.
Demand response: Changing electricity use at certain times to help the power system or respond to prices.
Direct-to-chip cooling: Cooling liquid flows through cold plates attached to chips to collect heat.
Dispatchable power: A power source that can start or change its output when needed, within its limits.
Distribution: The part of the grid that carries electricity from local substations toward customers.
Dry cooler: Equipment that transfers heat from a liquid to outdoor air without spraying water into that air.

E

Efficiency: How much useful work or output a system gets from the energy it uses.
Electrical charge: A property of matter that causes electrical forces. Moving charge creates electric current.
Electrode: A part where electric current enters or leaves a material. Battery and fuel-cell reactions happen at electrodes.
Electrolyte: A material that lets charged particles called ions move through a battery or fuel cell.
Electron: A tiny particle with negative electric charge. Electrons moving through wires carry current.
Emissions: Substances released into the surroundings, such as gases leaving a power plant.
Energy: An amount used or stored over time. For electricity, energy equals power multiplied by time.
EPA (Environmental Protection Agency): The U.S. government agency that protects human health and the environment.
Estimate: A careful best guess based on known facts. It can change when we learn more.
Evaporation: When liquid changes into gas, carrying heat away from what remains.
Exhaust: Gas leaving an engine or turbine after it has done work. Exhaust can still carry heat.

F

Fiber (fiber-optic cable): Thin strands of glass or plastic that carry information using light signals.
Filing: A formal document submitted to a public agency or court for review.
Fine-tuning: Extra training that adjusts an existing AI model for a narrower task.
Fission: Splitting an atom’s nucleus to release energy. Learn more
Forecast: An estimate of what may happen in the future.
Framework agreement: An agreement setting general terms for possible future orders. It may not guarantee every proposed purchase.
Frequency: How often something repeats each second. Grid frequency describes how often alternating current completes a cycle.
Fuel: A material used to release energy, such as natural gas, hydrogen or uranium.
Fuel cell: A device that turns fuel and oxygen into electricity without burning the fuel. Learn more

G

Gas turbine: A machine where hot, moving gas turns blades. A connected generator can make electricity.
Generator: A machine that changes movement into electrical energy.
Geothermal energy: Energy from heat inside Earth. Some power plants use that heat to make electricity.
GPU (graphics processing unit): A processor that performs many calculations at once. GPUs handle graphics and much of the work used for AI. Learn more
Gradient: Numbers that show how changing a model’s settings could change its errors. Training uses them to guide adjustments.
Grid: Connected power lines and equipment that carry electricity from power sources to users.
Grid connection: A link that lets a site receive electricity from the wider power system. Learn more
GW (gigawatt): A unit of power equal to one billion watts, or one thousand megawatts.
GWh (gigawatt-hour): A unit of energy equal to one gigawatt of power used for one hour.

H

Hardware: The physical parts of a computer system, such as chips, cables and drives.
HBM (high-bandwidth memory): Memory placed close to a processor to move large amounts of data quickly.
Heat: Energy moving from something warmer to something cooler.
Heat exchanger: Equipment that transfers heat between separate fluids without mixing them.
Heat rejection: Moving unwanted heat out of a system, usually into outdoor air or water.
Heat reuse: Using waste heat for another purpose, such as warming a nearby building.
High voltage: A large electrical push. Grids use high voltage to carry power over long distances with less energy lost.
Hydrogen: A light gas that can be used as fuel. Making hydrogen takes energy.
Hydropower: Electricity made by using moving water to turn a turbine connected to a generator.
Hyperscaler: A company running very large cloud computing systems.

I

Immersion cooling: Cooling equipment by placing it in a liquid that does not easily carry electric current.
Inference: Using a trained AI model to work on a new input and produce an answer. Learn more
Input: Information, energy or material that enters a system.
Interconnection queue: A waiting list for studies of proposed grid connections. Generator and large-customer connection processes can have different rules.
Inverter: Equipment that changes direct current into alternating current.
Ion: An atom or group of atoms with an electric charge.
Islanding: Running a local power system separately from the wider grid.
IT (information technology): Computers, storage and networks used to handle information.
IT load (information technology load): The electrical power used by computing equipment, rather than the whole building and its cooling systems.

K

kV (kilovolt): A unit of voltage equal to one thousand volts.
kW (kilowatt): A unit of power equal to one thousand watts.
kWh (kilowatt-hour): A unit of energy equal to one kilowatt of power used for one hour.

L

Large-load tariff: A power company’s price rules and conditions for customers using large amounts of electricity.
Latency: The time a message takes to travel or a system takes to respond. Learn more
Lawsuit: A dispute brought to a court for a decision.
Liquid cooling: A system that uses liquid to carry heat away from equipment. Learn more
Lithium-ion battery: A rechargeable battery that moves lithium ions between electrodes as it charges and discharges.
LLM (large language model): An AI model trained on large amounts of text to work with language.
Load: Equipment using electricity, or the amount of power it draws.
Load factor: Average power use divided by the highest power use during the same period.
Loop: A path that returns to its starting point, such as the route cooling liquid follows.

M

Machine learning: A way to build computer programs by learning patterns from examples.
Make-up water: Fresh water added to replace water lost from a cooling system.
Matrix: A table of numbers arranged in rows and columns. AI programs use calculations with matrices.
Memory: Storage holding information a computer needs during its work.
Microgrid: A local power network that can sometimes run separately from the larger grid.
Model: The AI program that makes answers by using patterns learned during training.
Modular: Made from units that can be built separately and joined together.
MW (megawatt): A unit of power equal to one million watts. Learn more
MWh (megawatt-hour): A unit of energy equal to one megawatt of power used for one hour.

N

N+1 redundancy: N means the number of units needed for the job. Plus one means one extra unit is available if a unit fails.
Natural gas: A fuel made mostly of methane. Burning or reacting it can supply energy and release carbon dioxide.
Network: Connections that let computers and other devices exchange data.
Neural network: An AI model made of connected layers that transform numbers to learn patterns.
Nuclear power: Electricity made using heat from reactions inside atoms, usually fission.

O

On-site: At the place where equipment or electricity will be used.
Operating capacity: Equipment capacity that has been put into service, rather than only announced or planned.
Optimizer: The part of AI training that uses results to adjust the model’s settings.
Output: Information, energy or material that leaves a system.
Oxygen: A gas in air that supports burning and takes part in many fuel-cell reactions.

P

Parallel computing: Doing several computing tasks at the same time.
Parameter: A number inside an AI model that training adjusts to help the model learn patterns.
Peak demand: The highest amount of power needed during a certain period.
Permit: Official permission required for certain activities or building work.
Potable water: Water safe enough for people to drink.
Power: How fast energy is delivered or used.
Power quality: How steady and usable the electrical supply is for connected equipment.
PPA (power purchase agreement): A deal between an electricity buyer and a power maker. They agree on a price for electricity over many years.
Pressure: How strongly a gas or liquid pushes against a surface.
Processor: A chip that follows instructions and performs calculations.
Prompt: The input or instructions someone gives an AI program.
PUE (power usage effectiveness): Total data center energy divided by computing equipment energy over the same time. Lower numbers mean less extra energy for cooling and other support.
Pump: A machine that pushes liquid through pipes.
PV (photovoltaic): Solar technology that turns sunlight directly into electricity. Solar panels use PV cells.

Q

Query: A request sent to a computer system, such as a search or an AI question.

R

Rack: A frame that holds computing equipment.
Rack density: How much electrical power equipment uses in one rack, often measured in kilowatts per rack.
Radioactive waste: Leftover material that gives off harmful radiation for a long time.
Rate: A price or charging rule, such as the cost for each unit of electricity used. Learn more
Reactor: Equipment that controls a nuclear reaction to produce heat.
REC (renewable energy certificate): A receipt showing that electricity was made from wind, sun or another renewable source. It does not show which electricity reaches your building.
Reclaimed water: Wastewater treated so it can be used again for an approved purpose.
Rectifier: Equipment that changes alternating current into direct current.
Redundancy: Extra equipment or paths that can take over when something fails.
Reliability: How consistently a system works when it is needed.
Renewable energy: Energy from sources naturally replenished, such as sunlight, wind and flowing water. Learn more
Resilience: How well a system can handle trouble and recover afterward.
Resistance: How much a material opposes electric current. Current through resistance produces heat.
Ruling: A court’s decision on a question brought before it.

S

Server: A computer that provides information or services to other computers over a network.
Shaft: A turning rod that connects machine parts and passes movement between them.
SMR (small modular reactor): A nuclear reactor designed with smaller units that can use factory-made parts.
Software: Programs and instructions that tell computer hardware what to do.
Solar power: Electricity or heat collected from sunlight.
SSD (solid-state drive): A device that stores data on memory chips instead of spinning disks.
Steam: Water in its gas form. Hot steam can turn a turbine.
Steam turbine: A machine whose blades are turned by steam. A connected generator can make electricity.
Stranded investment: Money spent on equipment or capacity that ends up being used less than expected.
Substation: A grid facility that switches power lines and often uses transformers to change voltage.
Supercapacitor: A device that stores energy electrically and can take in or release it very quickly.
Switchgear: Equipment that connects, disconnects and protects electrical circuits.

T

Tax abatement: A reduction in taxes that a government grants under certain rules.
TDP (thermal design power): A chip maker’s heat or power design rating used to plan cooling. Its exact meaning depends on the product.
Tensor Core: NVIDIA’s name for specialized chip hardware that speeds up certain calculations with tables of numbers.
Thermal energy: Energy linked to the motion of particles inside a material. Warmer objects generally have more of it than identical cooler objects.
Token: A piece of text or other data an AI model processes, such as part of a word.
Training: Adjusting an AI model using examples so it can learn patterns.
Training data: Examples used to teach an AI model patterns.
Transformer: A device that changes alternating-current voltage to suit the next part of an electrical system. Learn more
Transistor: A tiny electrical part that can switch or control current. Computer chips contain many transistors.
Transmission: Moving electricity over the wider grid, usually on high-voltage power lines.
Transmission vs. distribution: Transmission moves electricity across the wider grid. Distribution carries it from local substations toward customers.
Turbine: A machine with blades turned by moving gas, steam or water.
Two-system redundancy (2N): Two complete equipment systems, each able to handle the full job on its own.

U

UPS (uninterruptible power supply): Equipment that keeps electricity flowing briefly when the main supply fails or changes.
Uptime: The time equipment or a service is available to work.
Uptime tier: A level from 1 to 4 for a data center’s power and cooling setup. Higher levels add protection against shutdowns when parts fail.
Utility: A company or organization that supplies a service such as electricity.

V

Volt: A unit of voltage, the electrical push that can move charge.
Voltage: Electrical push: the difference that can drive current through a circuit.

W

Water consumption: Water used without returning it directly to the same local water source, often because it evaporates.
Water stress: When demand puts pressure on the amount or quality of water available in a place.
Water withdrawal: Water taken from a source for use. Some may be returned afterward.
Watt: A unit of power measuring how fast energy is delivered or used.
Wind power: Electricity made when moving air turns turbine blades connected to a generator.
Workload: A computing job or set of jobs a system needs to complete.
WUE (water usage effectiveness): A measure comparing a data center’s water use with the energy used by its computing equipment over the same period.

Z

Zoning: Local rules about how land may be used and what can be built there.

Reference checks: U.S. Energy Information Administration: Measuring Electricity · U.S. Department of Energy: Fuel Cell Basics. Related site explainers provide further sources.