A/B testing
Comparing variants across separated audiences using a defined measure. It needs correct allocation, adequate samples and controls against misleading conclusions.
Definition and sourcesKNOWLEDGE / FROM A TO Z
Glossary
Technology, explained clearly. Find a term, choose a letter or narrow the topic. Definitions include sources and their review date.
Terms 685 / 685
Above the fold
The page area visible before scrolling. Its boundaries depend on the device and window; loading priorities should support content actually visible there.
Definition and sourcesAbsolute URL
A URL including scheme and host, such as https://example.com/guide. It identifies the destination independently of the containing document's address.
Definition and sourcesAccount-based marketing
Marketing focused on selected businesses rather than a broad audience. Sales and marketing coordinate contacts, content and success criteria.
Definition and sourcesACME
A protocol for automating certificate issuance and renewal. Clients prove domain control through challenges such as DNS records or HTTP responses.
Definition and sourcesAd groups
Units organising related ads and delivery criteria within a campaign. A coherent theme helps match messages to queries or audiences.
Definition and sourcesADA (Americans with Disabilities Act)
A US law prohibiting disability discrimination in specified areas, including employment and public services. ADA is legislation; WCAG provides technical accessibility guidelines. They are not interchangeable.
Definition and sourcesAdversary-in-the-middle
An attack where an adversary intercepts communication and may read or modify it. TLS needs proper certificate verification to reduce this risk effectively.
Definition and sourcesAdware
Software that displays advertising, sometimes bundled with another application. Not all adware is malicious, but unwanted ads and tracking can affect privacy.
Definition and sourcesAffiliate marketing
A partnership model paying affiliates for attributed outcomes, such as sales. Programme rules define attribution, commission and prohibited activity.
Definition and sourcesAgile
An approach to software development emphasising collaboration, frequent value delivery and adaptation. Agile is not one methodology or an excuse to avoid planning.
Definition and sourcesAhrefs
An SEO analysis platform covering backlinks, keywords and website audits. Its metrics are provider estimates rather than scores assigned by Google.
Definition and sourcesAI (Artificial Intelligence)
A field developing systems for tasks such as recognising images, predicting outcomes and generating text. AI does not automatically imply human understanding. A model's confident answer can still be wrong.
Definition and sourcesAI Overviews
AI-generated summaries in Google results that may include source links. Availability depends on the query and market; website inclusion is not guaranteed.
Definition and sourcesAI text detector
A tool estimating whether text may have been AI-generated. Results can be wrong and should not alone determine authorship or responsibility.
Definition and sourcesAIDA
A model describing attention, interest, desire and action. It helps structure messages but does not prove that every purchase follows a linear path.
Definition and sourcesAJAX
A technique for fetching data through scripts without reloading the entire page. Despite its historical name, data need not be XML; JSON is common.
Definition and sourcesAlgorithm
A finite description of steps for solving a particular problem. In software, an algorithm describes data processing rather than merely its programming language.
Definition and sourcesALT attribute
An HTML attribute providing a text alternative for an image. It supports people using screen readers. The text depends on the image's purpose; purely decorative images normally use an empty alt. It is not a keyword list.
Definition and sourcesAltcoin
A customary name for a cryptocurrency other than bitcoin. It does not identify a single technology or security level. Projects differ in purpose, design, liquidity and risk.
Definition and sourcesAMP
A project and component set for pages with constrained, controlled behaviour. AMP is neither an indexing requirement nor a guarantee of better rankings.
Definition and sourcesAnchor text
The visible text of a clickable link. It should describe the destination clearly and fit the context rather than mechanically repeat keywords.
Definition and sourcesAngular
A framework for component-based web applications in the TypeScript ecosystem. Angular and the older AngularJS are different technologies with different support lifecycles.
Definition and sourcesAnsible
A tool automating system configuration and deployments through declared tasks. Playbooks make operations repeatable, while their correctness and safety still need review.
Definition and sources