3. Definitions
Key terms used throughout the methodology.
Aqueduct 4.0. The water risk database published by the World Resources Institute, from which the water stress categories on the scorecard are taken.
Availability Grade. A value from 1 to 5 placing a region's service availability percentage in a band, where 1 is the most complete band.
Availability Score. The availability grade published for a region, assigned from its service availability percentage.
Baseline Water Stress. The ratio of total water demand to available renewable surface and groundwater supply in an area, expressed as a percentage, as published in Aqueduct 4.0.
Basket Coverage Percentage. The share of the comparison basket for which a region publishes a price. An internal value, used to determine whether a cost grade is published.
Carbon Grade. A letter from A+ to F placing a region's average grid carbon intensity in a band, where A+ is the lowest intensity band.
CO₂e. Carbon dioxide equivalent. A metric that expresses the global warming potential of various greenhouse gases as the equivalent amount of carbon dioxide.
Comparison Basket. The fixed set of product categories on which every region of a provider is scored within one data version.
Cost Grade. A value from 1 to 5 placing a region's relative cost percentage in a band, where 1 is the least expensive band.
Country Fallback. The use of an Aqueduct country-level baseline water stress figure for a region that cannot be matched to a finer Aqueduct area.
Data Version. One complete run of the scoring over one refresh of the input data, identified by a version number carried on every row of output.
Grid Carbon Intensity. The average emissions produced per unit of electricity consumed from a given electricity grid, varying by region and time. Abbreviated as GCI.
Jenks Natural Breaks. A classification method that places class boundaries at the largest gaps in a distribution, minimising variation within each class and maximising it between classes.
On-Demand Price. A provider's published list price for one unit of a service bought without commitment, reservation, or dependence on spare capacity.
Price Ratio. A region's price for one basket product category, divided by the median price for that category across the provider's regions.
Pricing Score. The cost grade published for a region, assigned from its relative cost percentage.
Product Category. A fine-grained grouping of price list entries representing one comparable item of purchase, for example a single virtual machine type sold by the hour, or a single storage tier sold by the gigabyte-month.
Region. A named geographic location in which a provider sells services and publishes prices for them.
Relative Cost Percentage. The median of a region's price ratios, expressed as a percentage difference from the median. An internal value, from which the cost grade is assigned.
Service Availability Percentage. The count of product categories a region prices divided by the count priced by the provider's most complete region. An internal value, from which the availability grade is assigned.
Water Consumption. The water withdrawn and not returned to its source, for example through evaporation in a data centre cooling system. This methodology reports baseline water stress in the area a region occupies and does not report water consumption.
Water Stress Category. One of the five bands Aqueduct 4.0 assigns a baseline water stress percentage to, ranging from Low to Extremely High.