A plain-language glossary for web, design, marketing, data and artificial-intelligence projects. Each definition adds a practical use or caution to support clearer briefs and conversations.
Use these definitions to prepare a brief, review a proposal or ask a more precise question.
Results: 120
No definition matches. Try a shorter term or reset the search.
Terms are ordered alphabetically and explained for project decisions rather than as isolated technical theory.
A 301 redirect tells clients and search systems that a URL has permanently moved to a new address.
During a migration, it sends people and crawlers to the corresponding page rather than a dead end.
↑ Back to topA 404 response means the requested resource cannot be found at that address.
A useful 404 page supports onward navigation; important old URLs should redirect when a relevant replacement exists.
↑ Back to topA 503 response signals that a service is temporarily unavailable.
It suits a temporary interruption and may include a retry period, unlike a permanently removed page.
↑ Back to topAn acceptance criterion describes the observable result needed to approve a feature or deliverable.
Write it before implementation with a scenario, a testable condition and a named decision maker.
↑ Back to topAcceptance testing compares a site’s behaviour with expected outcomes in concrete scenarios.
Describe, prioritise, fix and retest each discrepancy before approving a release.
↑ Back to topAnswer Engine Optimisation describes work that makes an answer clear, reliable and usable by answer engines.
It does not replace SEO: the page must still be helpful, accessible, indexable and supported by evidence.
↑ Back to topAI evaluation compares a system’s outputs with criteria defined for a particular use.
Measure errors, robustness and the cost of human review before scaling a prototype.
↑ Back to topAlternative text describes the purpose or essential information of an image for people who cannot see it.
Its wording depends on context: a decorative image may have an empty alt attribute, while an informative chart needs an explanation.
↑ Back to topThe analytical unit is the object described by observations and results, such as a person, enterprise, establishment or territory.
Counting establishments and counting enterprises answer different questions; state the chosen level.
Apply this term to a decision →
↑ Back to topAnonymisation aims to prevent a person from being identified from a dataset over time.
Assess the risk of joining it with other sources before calling a dataset anonymous.
↑ Back to topAn API is an interface that lets software exchange data or trigger actions through documented rules.
It can connect a website to a payment service, CRM or trusted data source.
↑ Back to topPagination splits a result collection across several responses instead of transferring everything at once.
An import must traverse the required pages and account for changes to avoid missing or duplicate records.
↑ Back to topAn API quota limits calls or consumption over a period defined by the provider.
Check the limit, scope, response on exceedance and retry strategy before integrating.
↑ Back to topAttribution is the method used to connect a conversion to earlier marketing touchpoints.
No model fully explains a complex decision, so document assumptions and limitations.
↑ Back to topAutomation delegates repeatable tasks to a system that follows defined triggers and rules.
A maintainable automation has an owner, monitoring, documented exceptions and a manual fallback.
↑ Back to topAVIF is a compressed image format for the web that can be effective at reducing visual file sizes.
Provide a fallback format where the delivery context or tools require one.
↑ Back to topCache invalidation makes a stored version obsolete so an updated resource can be retrieved.
Versioned files support renewal; test after publication that visitors receive the intended version.
↑ Back to topA canonical URL is the preferred version indicated to search systems when several addresses contain the same or very similar content.
It supports consistent redirects and internal links, but cannot repair a confused architecture by itself.
↑ Back to topA content delivery network serves files from distributed locations closer to visitors.
It can reduce latency for images and scripts but does not replace file optimisation.
↑ Back to topCumulative Layout Shift measures unexpected movement of visible elements while a page is being used.
Reserving space for images and late-loading components helps prevent jumps.
↑ Back to topA content management system helps teams create, organise and publish pages without editing every page in code.
Selection depends on editorial workflow, permissions, integrations, maintenance and customisation needs.
↑ Back to topA cohort is a group defined by a common criterion and studied over a specified period.
For employment figures, retain period, size, response rate and definition of measured employment.
Apply this term to a decision →
↑ Back to topConsent is a freely given, specific, informed and unambiguous indication of agreement to a particular processing purpose.
It is not the only possible legal basis; collection and withdrawal must match the real use.
↑ Back to topA content audit inventories pages and assesses their usefulness, accuracy and role in user journeys.
It helps teams keep, improve, merge or remove material before a redesign.
↑ Back to topContent provenance explains who created or published information and which sources support it.
Visible authorship, dates, methods and corrections help readers assess reliability.
↑ Back to topContextual linking connects one page to another where a reader needs a related explanation.
Descriptive link text makes the destination clear and helps important pages be discovered.
↑ Back to topA conversion is a useful action completed by a visitor, such as an enquiry, sign-up, download or purchase.
Its value depends on a clearly defined outcome, not on the number alone.
↑ Back to topCore Web Vitals assess loading, responsiveness and visual stability through LCP, INP and CLS.
They are useful experience indicators but do not describe the complete quality of a service.
↑ Back to topA CRM centralises information and interactions concerning prospects, customers or partners.
It supports follow-up and shared history when access, quality and retention are governed.
↑ Back to topA data catalogue lists available datasets with their owner, definition and access conditions.
Add update frequency, licence and known limitations before inviting reuse by other teams.
↑ Back to topA data dictionary describes the meaning, format, units and expected values of dataset fields.
A column called date may refer to publication or observation; inspect its definition before comparing.
Apply this term to a decision →
↑ Back to topData governance defines who may create, access, change, secure and delete organisational data.
It also sets ownership, quality rules, retention and trusted sources.
↑ Back to topA join relates records from different datasets using keys and matching rules.
Check unique keys, one-to-many relationships and unmatched records to avoid multiplying or losing observations.
Apply this term to a decision →
↑ Back to topData lineage records where data came from, how it was transformed and where it is used.
It helps explain a figure, correct a source and assess the impact of a processing change.
↑ Back to topData quality describes whether information is fit for a specific use through accuracy, completeness, consistency and freshness.
Measure defects that change decisions; a large dataset can still be unsuitable for a critical task.
↑ Back to topA data schema describes the fields, types, relationships and constraints in a dataset.
Share it between producers and users to reduce integration and migration errors.
↑ Back to topA dataset’s vintage identifies its version or reference period.
Do not automatically equate it with retrieval date or the update date of a catalogue page.
Apply this term to a decision →
↑ Back to topA decision log records significant project choices with their date, context and owner.
It prevents the same discussion being reopened and makes the trade-offs understandable later.
↑ Back to topA design system combines shared principles, interface components and usage rules for consistent experiences.
It improves collaboration but does not replace user research or context-specific design decisions.
↑ Back to topDigital accessibility means designing content and services that more people, including disabled people, can use.
It covers structure, keyboard use, contrast, forms, media and assistive-technology compatibility.
↑ Back to topDigital ecodesign integrates environmental-impact reduction into the design and operation of a service.
It examines usefulness, uses, resources and dependencies; page weight does not capture the whole approach.
↑ Back to topDuplicate content is identical or very similar material accessible through several URLs.
Identify the version useful to readers, align links and canonicals, and consolidate variants without distinct value.
↑ Back to topE-E-A-T groups experience, expertise, authoritativeness and trust concepts used when assessing content quality.
It is not a public score or meta tag; show responsibility, sources, evidence, limits and relevant first-hand experience.
↑ Back to topAn editorial review checks whether a page still meets its purpose and whether facts, links and visuals remain accurate.
An updated date should reflect a real review rather than a timestamp change alone.
↑ Back to topAn evaluation set contains representative cases used to measure a system’s behaviour.
Include difficult examples, expected errors and real use cases rather than only a polished demonstration.
↑ Back to topEXIF is metadata embedded in some image files, including capture settings and descriptions.
Remove sensitive fields before publication and do not use EXIF as a substitute for page alt text.
↑ Back to topExit cost covers spending required to leave a solution and resume work elsewhere.
Include export, migration, handover and internal effort; ask whether exported files are actually reusable.
Apply this term to a decision →
↑ Back to topFaceted navigation combines multiple criteria to narrow a list of results.
Empty states, usability and generated URLs need review to avoid confusing journeys.
↑ Back to topField data describes the experience of real visitors on their own devices and networks.
It complements laboratory tests and requires a clear collection method and respect for privacy.
↑ Back to topFirst-party data is collected directly by an organisation through its own relationships and services.
It still needs a defined purpose, proportionate collection, protection and respect for people’s rights.
↑ Back to topThe GDPR governs personal-data processing in the European Union and strengthens people’s rights.
Organisations need clear purposes, proportionate collection, secure access and transparent information.
↑ Back to topGenerative AI produces text, images, audio, code or other material from instructions and learned patterns.
Outputs require risk-based checking because they can be incorrect, incomplete or unsuitable.
↑ Back to topGenerative Engine Optimisation aims to make content understandable, reliable and usable in generative answer experiences.
Clear entities, direct answers, original evidence, sources and crawlable technical foundations support this work.
↑ Back to topGeocoding associates a geographic location with a description of a place, such as an address.
An ambiguous match requires review; a coordinate establishes neither identity nor someone’s presence.
Apply this term to a decision →
↑ Back to topHreflang connects equivalent language or regional versions so search engines can present the appropriate page.
Each page should reference itself and its equivalents with accessible, canonical and reciprocal URLs.
↑ Back to topHTTP caching allows a previously fetched response to be reused for a defined time.
Appropriate cache rules speed up stable assets while allowing changed content to refresh.
↑ Back to topAn idempotent operation has the same intended effect when repeated with the same parameters.
This property supports safe retries; repeated payment or message requests should specifically avoid duplicates.
↑ Back to topImage compression reduces the bytes needed to store and deliver a visual.
Compare the result at the real display size; a small file is useful only when important details remain legible.
↑ Back to topAn image licence states which uses the rights holder permits for a visual.
Check alteration, distribution and credit conditions before using a photo in a guide, card or social preview.
↑ Back to topImage metadata is information embedded in a file, such as its creator, description or camera settings.
It helps manage an asset but can be removed by processing; visible context and alternative text remain essential.
↑ Back to topAn image sitemap tells search engines which visuals are associated with public pages.
It helps discovery but does not guarantee an image will appear in search results.
↑ Back to topIndexNow is a protocol for notifying participating search engines when a URL is added, changed, moved or deleted.
It complements an XML sitemap, which remains the durable inventory of discoverable preferred URLs.
↑ Back to topInformation architecture organises content, labels and navigation paths within a service.
It should help people find answers without knowing the organisation’s internal vocabulary.
↑ Back to topInteraction to Next Paint assesses a page’s overall responsiveness during user interactions.
Slow responses may call for less JavaScript work or better scheduling of tasks.
↑ Back to topInternal linking connects pages on the same site so people and crawlers can understand their relationships.
Descriptive anchors and contextual links make important material easier to discover.
↑ Back to topInteroperability is the ability of separate systems to exchange data and use it correctly.
Check formats, identifiers, update rules and error handling, not merely whether an API exists.
↑ Back to topIPTC metadata can record a visual creator, rights, description and licence information.
It helps rights management when the file format and publishing pipeline retain the metadata.
↑ Back to topIsolated restoration recovers a copy in a separate environment to verify its data and operation.
Disable outgoing actions such as email or payment so the test does not trigger real operations.
↑ Back to topJSON-LD adds machine-readable structured data without mixing it into the visible HTML content.
Declared entities and properties must match information people can actually see on the page.
↑ Back to topA KPI is an indicator selected to track a specific objective and support a decision.
A useful KPI has a definition, owner, context and possible action.
↑ Back to topLazy loading delays retrieval of a media item farther down the page until it becomes useful.
Avoid delaying the main image visible on arrival because that can slow its appearance.
↑ Back to topLargest Contentful Paint measures how long it takes to display the largest visible element in the initial viewport.
The main image, server response and blocking resources can influence this measure.
↑ Back to topA large language model is trained to process and generate language from large collections of data.
It can summarise or classify material but does not guarantee factual accuracy or human understanding.
↑ Back to topA mandatory criterion excludes an option when an essential requirement is absent, regardless of its scores elsewhere.
Assess it separately from a weighted average so a major incompatibility is not concealed.
Apply this term to a decision →
↑ Back to topA measurement plan connects outcomes, tracked events, indicator definitions and decisions.
Assign an owner to each measure and check that it works before using it in a dashboard.
↑ Back to topA mobile crop adapts an image composition to a narrow screen while keeping its essential subject.
Check the face, object or central information at several widths before publishing a variant.
↑ Back to topA minimum viable product is a deliberately limited but useful version built to test an assumption with real users.
It is a learning scope, not an excuse for unreliable quality.
↑ Back to topA named entity is an identifiable person, organisation, place or concept in content.
Consistent naming, precise descriptions and links to official sources reduce ambiguity.
↑ Back to topNo-code uses visual interfaces and configurable components to build sites, applications or automations.
It can accelerate delivery but still needs decisions about data, security, ownership and maintenance.
↑ Back to topObservability helps a team understand a service through its measurements, logs and traces.
Choose signals tied to critical journeys and assign someone to investigate alerts.
↑ Back to topFrance’s Open Licence 2.0 permits reuse of public information, including copying, adaptation and commercial exploitation, under its terms.
Check that it applies to the dataset and retain producer attribution and the information’s update date.
Apply this term to a decision →
↑ Back to topA performance budget sets limits for transferred weight, requests or time on a page template.
It helps govern new images and third-party services, using representative mobile checks.
↑ Back to topA primary source directly publishes data, a rule, research or documentation for which it is responsible.
Trace claims to the source where possible and check its date, scope and limitations.
↑ Back to topA dependency is an input or decision required before a task can proceed or be accepted.
Content, access, legal decisions and third-party APIs belong in the schedule with named owners.
↑ Back to topPseudonymisation replaces direct identifiers with separate references without necessarily preventing re-identification.
Protect the mapping table and continue to handle the information as personal data.
↑ Back to topRetrieval-augmented generation combines a generative model with information retrieved from selected sources.
Quality depends on retrieval, document freshness, access rights, citations and answer verification.
↑ Back to topResponsive design adapts a layout to different screen sizes and device capabilities.
The interface should remain readable, operable and complete across mobile, tablet and desktop.
↑ Back to topA responsive image offers a suitable size or crop for the screen and layout.
Srcset or a picture element can supply variants while an img element provides a fallback URL.
↑ Back to topRGAA is the French reference framework used to assess digital accessibility and organise compliance work.
It provides test criteria and methods within the applicable French legal context.
↑ Back to topRGESN is the French reference framework for ecodesign of digital services.
It supports examination of service choices; citing it does not establish that its criteria have been assessed.
↑ Back to topRisk analysis identifies events that could prevent an outcome and considers their consequences.
For each priority risk, record a warning signal, a mitigation and the person monitoring it.
↑ Back to topFrance’s National Register of Professional Certifications lists qualifications that lead to an occupation.
Inspect the exact record for validity, level, skills and authorised organisations before comparing training.
Apply this term to a decision →
↑ Back to topRobots.txt tells crawlers which areas of a site they may or may not request.
It does not secure private information or replace a noindex directive on an accessible page.
↑ Back to topA rollback restores a previous version when a release causes a major problem.
The procedure should identify backups, owners and data that may have changed since deployment.
↑ Back to topRPO expresses the maximum amount of data an organisation is prepared to lose after an incident.
It informs backup frequency and should be tested through a realistic recovery scenario.
↑ Back to topRTO expresses the target time for restoring a service after an interruption.
Compare that target with actual restoration capacity, dependencies and staff availability.
↑ Back to topReal User Monitoring measures the experience of authorised real visits to a website.
It complements laboratory tests by reflecting varied devices, networks, pages and interactions.
↑ Back to topSearch intent is the need a person is trying to meet behind a query.
A useful page addresses that need with suitable depth, examples and a clear next step.
↑ Back to topSelection bias occurs when observed data represents some situations or populations more than others.
An average may hide missing audiences; check coverage before generalising a result.
↑ Back to topSearch engine optimisation helps relevant pages be crawled, understood and found in search.
It combines useful content, architecture, technical quality, internal links and credible evidence.
↑ Back to topA service level agreement defines support or availability commitments.
It should state how results are measured, exclusions, response times and responsibilities.
↑ Back to topAn SLO is a measurable service-level objective for a defined period and user population.
Specify what counts as success, the measurement window and the action taken when the objective is missed.
↑ Back to topA staging environment lets a team review a site version before visitors see it.
It should reproduce important journeys without exposing unnecessary real data or being indexed accidentally.
↑ Back to topStructured data explicitly describes entities and relationships with a shared vocabulary such as Schema.org.
It can improve understanding but does not guarantee a rich result or ranking.
↑ Back to topSearch experience optimisation connects discoverability with the quality of the journey after a visit begins.
It aligns search intent with clarity, trust, speed and task completion.
↑ Back to topSynchronisation reconciles data copies to propagate changes across locations.
It can also propagate deletion; check recoverable versions before treating it as a backup.
↑ Back to topA taxonomy is a coherent set of categories and terms used to classify content or resources.
Stable classification rules improve filters, internal links and editorial maintenance.
↑ Back to topTechnical debt is the future cost created by implementation choices that make later changes harder.
Manage it by documenting trade-offs and reserving time for valuable corrections.
↑ Back to topTotal cost of ownership covers spending needed to acquire, operate, maintain and exit a solution over a defined period.
State the duration and assumptions; compare licences, integration, support, internal effort and data export consistently.
↑ Back to topUser interface refers to the visual and interactive elements through which someone uses a digital product.
Controls, typography, colour and states should form a coherent accessible language.
↑ Back to topUptime is the share of a measured period during which a service responds correctly to requests.
Its meaning depends on the period and criteria; a page that responds but cannot be used is still a problem.
↑ Back to topA usability test observes someone completing a representative task with a product or prototype.
Record what they understand, where they hesitate and whether they finish unaided, then fix recurring obstacles.
↑ Back to topA user journey describes the steps a person takes to complete a goal in a service.
It reveals questions, obstacles and information needed at each point.
↑ Back to topUser research investigates the needs, constraints and behaviour of people affected by a service.
Combine open questions with task observation; stated preference is not the same as successful use.
↑ Back to topUser experience describes the overall quality a person experiences before, during and after using a service.
It depends on usefulness, ease, accessibility, trust and real context.
↑ Back to topWCAG are W3C recommendations for making web content more perceivable, operable, understandable and robust.
They underpin many accessibility standards and should be combined with human testing and governance.
↑ Back to topCrawling is the process through which a robot discovers and requests URLs, links and resources to understand a site.
Clear HTML links, current sitemaps and reliable server responses support discovery.
↑ Back to topA webhook sends information from one service to another when a defined event occurs.
It can report a payment or form submission so another process begins automatically.
↑ Back to topWebP is a web image format that can reduce the size of a photograph or illustration at comparable visual quality.
The outcome depends on the image and compression level, so inspect the export.
↑ Back to topAn XML sitemap lists the canonical URLs a site wants search engines to discover.
It helps signal new or changed pages but does not guarantee crawling or indexing.
↑ Back to topExplore the expertise families, then use the practical guides to prepare a clearer request.
