A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Glossary: AI & Digital from A to Z

The most important terms from AI, web development and digital marketing - explained in brief.

A

A/B Test
A method in which two variants of a page or element are tested at the same time to find out which version converts better. Essential for data-driven optimization.
Accessibility
Designing digital content so that everyone can use it, including people with visual, hearing, motor or cognitive impairments. Increasingly a legal requirement in the EU (European Accessibility Act since 2025).
Agentic AI
AI systems that plan tasks on their own, use tools and interact with their environment to reach multi-step goals - without needing human input for every step.
AI (Artificial Intelligence)
Technologies that replicate human cognitive abilities such as learning, language understanding, pattern recognition and problem solving in computer systems. Includes machine learning, deep learning, natural language processing and other subfields.
AI Agent
An AI agent is software based on a language model that pursues goals on its own, plans work steps and uses tools such as search, databases or other programs to do so. AI agents automate multi-step tasks but need clear boundaries and oversight.
AI Evaluation (Evals)
Evaluating AI systems means systematically testing, with defined test cases and criteria, how reliably a model or AI application works. Evals make quality measurable and show whether changes to prompts, models or data actually bring improvements.
AI Literacy Obligation (Art. 4 AI Act)
The AI literacy obligation under Art. 4 of the EU AI Act requires providers and deployers of AI systems to take measures so that their staff have sufficient AI literacy. It has applied since February 2, 2025 and also affects companies that simply use AI tools in their everyday work.
Alt Text
Alt text is a short text description of an image in the HTML alt attribute. It makes images accessible to screen readers and helps search engines and AI systems understand what an image shows.
API (Application Programming Interface)
A standardized interface that lets software systems communicate and exchange data with each other. APIs are the backbone of modern web architectures and AI integrations.
Austrian Accessibility Act (BaFG)
The Austrian Accessibility Act (Barrierefreiheitsgesetz, BaFG) implements the European Accessibility Act and has applied since June 28, 2025. It requires companies to make certain products and services accessible, such as online stores, banking services and e-books; microenterprises are exempt for services.

B

Backlink
An incoming link from an external website - one of the most important ranking factors for search engines. Quality beats quantity: one link from an authoritative domain is worth more than many from weak sites.
Benchmark (AI)
An AI benchmark is a standardized test used to compare how well AI models perform on specific tasks such as reading comprehension, coding or math. Strong benchmark results do not guarantee that a model will perform best in your own use case.
Bias (AI)
Bias refers to systematic distortions in AI output, usually caused by one-sided or unbalanced training data. Bias can lead to unfair decisions, for example in candidate selection or lending, which is why it has to be checked deliberately.
Bounce Rate
The percentage of visitors who leave a website after viewing only a single page. High values can point to irrelevant content, slow load times or the wrong kind of traffic.
Brand Voice
The distinctive voice and tone of a brand across all communication - from the website and social media to customer support. A consistent brand voice builds trust and recognition.

C

Chain-of-Thought
Chain-of-thought is a technique in which a language model solves a task in traceable intermediate steps instead of giving the answer directly. This improves results especially for calculation, logic and planning tasks.
Content Strategy
Planning, creating, distributing and maintaining content to reach defined business goals. Includes topic planning, channel selection, tone of voice and measuring success.
Context Window
The context window is the maximum amount of text, measured in tokens, that a language model can take into account in a single request, including input, conversation history and response. A larger context window allows long documents to be analyzed but usually increases cost and response time.
Conversion Rate
The ratio of visitors to actual conversions - purchases, sign-ups, downloads or other actions. A key metric in digital marketing, expressed as a percentage.
Core Web Vitals
Metrics defined by Google to measure real-world user experience: Largest Contentful Paint (LCP, loading), Interaction to Next Paint (INP, responsiveness) and Cumulative Layout Shift (CLS, visual stability). They feed directly into Google rankings.
Corporate Design
A company's visual identity: logo, colors, typography, imagery and all design elements that create recognition and communicate the brand identity to the outside world.
CRO (Conversion Rate Optimization)
Systematically improving web pages so that a larger share of visitors become customers - through A/B tests, heatmap analysis and data-driven iterations.
Cyber Resilience Act (CRA)
The Cyber Resilience Act is an EU regulation that sets binding cybersecurity requirements for products with digital elements, meaning connected hardware and software. It has been in force since December 2024; reporting obligations for actively exploited vulnerabilities apply from September 2026, the remaining obligations from December 2027.

D

Data Act
The Data Act is an EU regulation governing access to and use of data from connected products and related services. It has applied since September 12, 2025 and, among other things, gives users the right to obtain and share the data their devices generate; it also makes it easier to switch between cloud providers.
Data Processing Agreement (DPA, German: AVV)
A DPA is the contract required under Art. 28 GDPR when a service provider processes personal data on behalf of a company, for example a hosting, newsletter or AI provider. It sets out the purpose, scope, rights to issue instructions and security measures for the processing.
Deepfake
A deepfake is an image, audio or video created or manipulated with AI that looks deceptively real and makes real people appear to say or do things. The EU AI Act requires such content to be labeled as artificially generated.
Deployment
The process of releasing and running software or a website on a production server. Modern deployments run automatically through CI/CD pipelines.
Design System
A collection of reusable UI components, guidelines and standards that enables consistent product and brand experiences across all touchpoints. Saves development time and safeguards quality.
Digital Markets Act (DMA)
The Digital Markets Act is an EU regulation that imposes special obligations on very large platform operators, known as gatekeepers, to ensure fair competition. These include bans on favoring their own offerings and requirements for interoperability.
Digital Services Act (DSA)
The Digital Services Act is an EU regulation that requires online platforms and other intermediary services to be more transparent and to deal with illegal content. It has applied in full since February 2024, with especially strict obligations for very large platforms and search engines.

E

E-Commerce
Trade conducted over the internet, covering all digital touchpoints along the customer journey - from product discovery and purchase to after-sales service.
eIDAS 2.0
eIDAS 2.0 is the revised EU regulation on electronic identification and trust services such as qualified electronic signatures and seals. It has been in force since May 2024 and provides the legal basis for the European Digital Identity Wallet (EUDI Wallet).
Embedding
A representation of text, images or other data as numerical vectors in a high-dimensional space. Similar content gets similar vectors - the foundation of semantic search and RAG systems.
ePrivacy
ePrivacy refers to the EU rules protecting privacy in electronic communications, above all the ePrivacy Directive. Among other things, it requires consent before non-essential cookies and tracking can be used; in Austria it is implemented through the Telecommunications Act (Telekommunikationsgesetz, TKG). A planned ePrivacy Regulation was never adopted.
EU AI Act
The EU AI Act is the world's first comprehensive law regulating artificial intelligence and classifies AI systems by risk. It entered into force on August 1, 2024 and applies in stages: prohibitions and the AI literacy obligation since February 2025, obligations for general-purpose AI models since August 2025, with further obligations following step by step until 2027.
EUDI Wallet
The EUDI Wallet (European Digital Identity Wallet) is a digital wallet on your smartphone that lets citizens and businesses identify themselves across the EU, present credentials such as a driver's license or certificates and sign documents with a qualified signature. It is based on eIDAS 2.0, which requires member states to provide such a wallet.
European Accessibility Act (EAA)
The European Accessibility Act is an EU directive that sets accessibility requirements for selected products and services, including e-commerce, banking services, e-books and passenger transport. The national implementations have applied since June 28, 2025, in Austria through the Austrian Accessibility Act (BaFG).

F

Favicon
A small icon (usually 16x16 or 32x32 pixels) shown in the browser tab, in bookmarks and in the address bar. An important building block of a brand's visual identity on the web.
Few-Shot Prompting
Few-shot prompting is a prompting technique in which the language model is given a few examples of the desired task and output format. This makes the model deliver more consistent results without fine-tuning.
Fine-Tuning
Further training of a pre-trained AI model on specific data to specialize it for a particular use case or subject area. Cheaper than training from scratch.
Foundation Model
A foundation model is a large AI model pre-trained on broad amounts of data that serves as the basis for many different applications. Large language models are the best-known foundation models; they can be adapted to specific tasks through prompting, RAG or fine-tuning.
Framework
A programming scaffold with reusable building blocks for developers. Examples: React, Vue and Next.js for frontends; Laravel and Django for backends.
Function Calling (Tool Use)
Function calling is the ability of a language model to call external functions or tools in a structured way, such as a database query, a web search or an API. It is the technical foundation for AI agents that don't just answer but take action.

G

GDPR (General Data Protection Regulation)
The GDPR (German: DSGVO) is the European data protection law and has applied since May 2018; it governs how personal data is collected, processed and stored. Violations can be punished with fines of up to 20 million euros or 4% of worldwide annual revenue. In Austria it is supplemented by the Data Protection Act (Datenschutzgesetz, DSG).
Generative AI
Generative AI refers to AI systems that create new content such as text, images, audio, video or code. It is usually based on large language models or diffusion models and is fundamentally changing marketing, content production and software development.
GEO (Generative Engine Optimization)
Optimizing content for AI-powered search engines and large language models such as ChatGPT Search, Perplexity or Google AI Overviews. Adds new requirements for structure, authority and machine-readable clarity to classic SEO.
GPAI (General-Purpose AI)
In the EU AI Act, GPAI stands for general-purpose AI models, meaning versatile models such as large language models. Since August 2025, their providers have had obligations regarding technical documentation, copyright and transparency about training data, with additional requirements for models with systemic risk.
Gradient Descent
A core algorithm for training AI models. It iteratively adjusts the model parameters by moving in the direction of the steepest descent of the loss function, reducing the error step by step.
Grounding
Grounding means anchoring AI answers in verifiable sources such as company documents, databases or search results. Grounding reduces hallucinations and makes it possible to cite sources in the answers.
Guardrails
Guardrails are safeguards that check the inputs and outputs of an AI system and prevent unwanted behavior, such as disclosing confidential data, offensive content or answers outside the intended topic. They are implemented through rules, filters or additional checking models.

H

Hallucination (AI)
A phenomenon in large language models where the model produces factually wrong information with apparent confidence and fluent language. It happens because LLMs calculate probabilities rather than look up facts. Quality assurance of AI output is the responsibility of the client.
Headless CMS
A content management system that strictly separates the backend (content management) from the frontend (presentation) and delivers content via APIs. Allows maximum flexibility when publishing to different channels.
High-Risk AI System
Under the EU AI Act, a high-risk AI system is an AI system that poses significant risks to health, safety or fundamental rights, for example in recruitment, credit scoring, education or critical infrastructure. Such systems are subject to strict requirements for risk management, data quality, documentation and human oversight.
hreflang Attribute
The hreflang attribute tells search engines which language or country version of a page is intended for which users. It prevents, for example, Austrian and German versions of a website from being treated as duplicate content.
Human-in-the-Loop
Human-in-the-loop describes an approach in which people review, approve or correct AI results before they take effect. The principle increases quality and safety and corresponds to the human oversight the EU AI Act requires for high-risk systems.

I

Inbound Marketing
A strategy that attracts potential customers with helpful, relevant content instead of interrupting them with advertising. Blog posts, guides, videos and podcasts are typical inbound formats.
Indexing
Indexing is the inclusion of a web page in a search engine's database after a crawler has captured it. Only indexed pages can appear in search results.
Inference
Inference means using a trained AI model to generate an answer or prediction for a specific input. The cost and speed of inference largely determine how economical an AI application is to run in day-to-day operation.
ISO/IEC 27001
ISO/IEC 27001 is the international standard for information security management systems (ISMS). Certification shows that a company systematically identifies and manages information security risks, and it is often a requirement when selecting IT and cloud service providers.
IT Infrastructure
The technical foundation of a digital solution: servers, networks, databases, security systems, backup solutions and monitoring. Invisible when it works - and critical when it doesn't.

J

Jailbreak
A jailbreak is an attempt to get around an AI model's safety rules with cleverly worded inputs so that it produces unwanted or prohibited content. Providers and developers counter jailbreaks with guardrails, testing and ongoing monitoring.
JavaScript
A programming language that runs in the browser and enables dynamic interactions, animations and asynchronous data exchange on the web. With Node.js it can also run on the server - today the most widely used programming language in the world.
JSON
JSON (JavaScript Object Notation) is a lightweight, text-based data format for exchanging structured data between systems. It is the standard format of many APIs and is also used for structured output from language models.
JSON-LD
JSON-LD (JSON for Linked Data) is the format recommended by Google for embedding Schema.org structured data in a web page. JSON-LD helps search engines and AI systems clearly understand content such as organizations, products or FAQs.
JWT (JSON Web Token)
A JSON Web Token is a compact, digitally signed token that applications use to securely transmit a user's identity and permissions. JWTs are widely used for authentication in web apps and APIs.

K

Keyword
A search term or phrase that users enter into search engines. The basis of every SEO and content strategy. Short-tail keywords have high volume and high competition; long-tail keywords are more specific and often convert better.
KPI (Key Performance Indicator)
A measurable metric that quantifies progress toward a defined goal. Good KPIs are specific, measurable, achievable, relevant and time-bound (SMART criteria).

L

Landing Page
The page users are taken to after clicking an ad, an email link or an organic search result. Usually built around a single, clear call to action - without distracting navigation.
Latency
The delay between a request and the first response. In AI, the time until the first generated token (time to first token). On the web, the time until the first server response (time to first byte).
Lighthouse
An open-source auditing tool from Google that automatically checks web pages for performance, accessibility, SEO, best practices and PWA criteria. Gives a score from 0-100 per category.
LLM (Large Language Model)
An AI model trained on enormous amounts of text that can understand, generate and transform natural language. The basis of modern AI assistants such as ChatGPT, Claude, Gemini, Llama and Mistral.
llms.txt
llms.txt is a proposed convention in which a website provides a Markdown file in its root directory with a compact overview of its most important content for language models. The file is not an official standard but is increasingly used as part of GEO.
Local AI (On-Premises)
Local AI means running AI models on your own hardware or servers instead of through a provider's cloud services. Local AI keeps sensitive data inside the company and makes GDPR compliance easier, but requires suitable computing power and maintenance.

M

Machine Learning
A subfield of AI in which algorithms learn from data, recognize patterns and make predictions - without being explicitly programmed for each use case.
MCP (Model Context Protocol)
The Model Context Protocol is an open standard that gives AI applications a uniform way to access external data sources and tools, such as files, databases, calendars or business software. MCP was initiated by Anthropic and is now supported by many providers.
Meta Tag
An HTML element in the page head that contains metadata - for example the page description for search engines, the viewport for mobile display or Open Graph data for social media previews.
Mixture of Experts (MoE)
Mixture of experts is a model architecture in which an AI model consists of several specialized subnetworks, only some of which are activated for each request. This lowers the computing effort during inference without giving up the performance of a large model.
Mobile First
A design principle in which the mobile view of a website is designed first and the desktop version builds on it through progressive enhancement. It reflects real user behavior: more than 60% of visits come from mobile devices.
Multimodal
AI systems that can combine several types of input - text, images, audio, video or documents at the same time. Current model families from OpenAI, Anthropic, Google and Mistral are multimodal and can analyze photos, charts or PDF files, for example.

N

Neural Network
A neural network is a computational model made of many interconnected nodes, loosely inspired by the structure of the brain, that learns patterns from data. Deep neural networks (deep learning) are the foundation of today's language, image and speech recognition models.
Newsletter
Email communication sent regularly to subscribers. Still one of the most effective channels in digital marketing - a direct line to your own audience without depending on algorithms.
NIS2 Directive
NIS2 is the EU directive on measures for a high common level of cybersecurity. It extends obligations for risk management and incident reporting to many more sectors and to medium-sized companies. Management is liable for implementation; in Austria it is being implemented through a new Network and Information Systems Security Act (Netz- und Informationssystemsicherheitsgesetz, NISG).
NLP (Natural Language Processing)
A subfield of AI concerned with machines understanding, analyzing and generating human language. The basis of translation tools, sentiment analysis, chatbots and large language models.
Noindex
Noindex is an instruction, set via a meta tag or HTTP header, that asks search engines not to include a page in their index. It is useful for thank-you pages, internal search results or test environments, for example.

O

OCR (Optical Character Recognition)
OCR is the automatic recognition of text in images and scanned documents. Modern multimodal AI models go beyond classic OCR and also capture tables, layouts and the relationships between pieces of content.
Off-Page SEO
Off-page SEO covers all measures outside your own website that strengthen authority and visibility, above all backlinks, mentions in media and industry directories, and reviews. For GEO, brand mentions in trustworthy sources become even more important.
On-Page SEO
All optimization measures directly on your own website: content quality, keyword integration, meta tags, heading structure, internal linking, load time and image data.
Open Graph
Open Graph is a protocol of meta tags that defines the title, description and image shown when a page is shared on social networks and messengers. Well-maintained Open Graph data ensures attractive, on-brand link previews.
Open Source
Software whose source code is publicly visible and free to use and modify. In AI, the open-source movement is growing with models such as Llama, Mistral and Stable Diffusion.
Open-Weight Model
An open-weight model is an AI model whose trained weights are publicly available for download, so it can be run and adapted on your own infrastructure. Examples include models from Meta (Llama) and Mistral; the license terms vary and are not always open source in the strict sense.

P

PageRank
Google's original algorithm for assessing the relevance of a web page based on the number and quality of incoming links. Still an important ranking factor.
Parameters (AI Model)
Parameters are the numerical values an AI model learns during training, which determine how it processes inputs. The number of parameters, often given in billions, is a rough indication of a model's size and computing needs, but not a measure of quality on its own.
Prohibited AI Practices
Prohibited AI practices are applications with unacceptable risk that have been banned under Art. 5 of the EU AI Act since February 2, 2025. They include social scoring, manipulative techniques that cause harm to people, and emotion recognition in the workplace or in educational institutions, apart from narrowly defined exceptions.
Project Brief
A structured document at the start of a project that defines the goals, target audiences, budget, timeline, deliverables and expectations of everyone involved. A good brief is the most important investment in a project.
Prompt Engineering
The technique of deliberately wording instructions, context and examples for AI language models. Well-designed prompts lead to more precise, more reliable and more useful output.
Prompt Injection
Prompt injection is an attack in which hidden or manipulated instructions in inputs, web pages or documents trick an AI system into taking unwanted actions. AI agents with access to tools and data in particular must be protected against it.
Pseudonymization
Pseudonymization means processing personal data in such a way that it can no longer be attributed to a person without additional information kept separately. Pseudonymized data is still personal data under the GDPR but lowers the risk, for example when using AI.
PWA (Progressive Web App)
A web application that uses modern browser APIs to behave like a native app: works offline, can be launched from the home screen, supports push notifications and is fast - without having to be published in an app store.

Q

QR Code
A QR code is a two-dimensional code that stores information such as URLs, contact details or payment data and is read with a smartphone camera. QR codes connect print media, packaging and posters directly with digital offerings.
Quality Assurance of AI Output
Quality assurance of AI output covers all measures used to check AI-generated content for accuracy, completeness, legal compliance and brand consistency before it is used. This includes fact-checking, approval processes with a human in the loop and automated evaluations.
Quantization
Quantization makes an AI model smaller by storing its parameters with lower numerical precision, for example 8 or 4 bits instead of 16 bits. This lets models run faster and on less powerful hardware, usually with only a small loss in quality.
Quantum Computing
Quantum computing uses quantum mechanical effects such as superposition and entanglement to potentially solve certain computational problems much faster than classical computers. The technology is still mostly at the research stage but is considered relevant in the long term for encryption, materials research and optimization.
Query Fan-out
Query fan-out is a technique used by AI-powered search systems in which a user's question is automatically broken down into several sub-queries whose results are then combined into one answer. For GEO this means: content should also cover related sub-questions of a topic.

R

RAG (Retrieval-Augmented Generation)
A technique in which a language model actively draws on an external, up-to-date knowledge base when generating its answer. Reduces hallucinations and enables AI applications that use your own company knowledge.
Reasoning Model
A reasoning model is a language model that goes through several internal thinking steps before answering, which lets it solve complex tasks in logic, math, programming or planning more reliably. The higher quality usually comes with longer response times and higher costs.
Reranking
Reranking is a second sorting step in search and RAG systems in which a specialized model reorders the results found earlier by their actual relevance. This gives the language model the most suitable information for its answer.
Responsive Design
A design approach in which web layouts automatically adapt to different screen sizes and devices through flexible grids, images and CSS media queries.
Rich Snippet
A rich snippet is an enhanced search result that shows additional information such as star ratings, prices, FAQs or event dates alongside the title and description. It requires correctly marked-up structured data, for example in JSON-LD.
Risk Categories (AI Act)
The EU AI Act sorts AI systems into risk categories: unacceptable risk (prohibited), high risk (strict requirements), limited risk (transparency obligations, for example for chatbots and deepfakes) and minimal risk (no special obligations). The classification depends on the intended purpose, not on the technology used.
Robots.txt
A text file in a website's root directory that tells search engine crawlers which areas they may crawl. Today it is also relevant for AI crawlers such as GPTBot or ClaudeBot.

S

Schema.org
Schema.org is a shared vocabulary of the major search engines for marking up structured data on web pages. With Schema.org markup, companies, products, articles or FAQs can be described in a machine-readable way, which supports SEO and GEO.
Scope of Work
A clear definition of the work covered by a project contract: what is delivered, at what quality, by when - and explicitly what is not included. Protects both sides from misunderstandings.
Semantic HTML
Using HTML elements according to the meaning of their content: <article>, <nav>, <main> instead of generic <div> elements. Improves accessibility, SEO and machine readability.
SEO (Search Engine Optimization)
All technical and content measures that improve visibility in organic search results. Includes on-page SEO, technical SEO, off-page SEO and content strategy.
SLA (Service Level Agreement)
A contractual agreement between service provider and client covering quality, availability, response times and consequences if these are not met. Central to professional agency-client relationships.
SPA (Single Page Application)
A web application that runs entirely within a single HTML page and loads content dynamically with JavaScript - without full page reloads. React, Vue and Angular are the dominant SPA frameworks.
SSG (Static Site Generator)
A tool that generates static HTML files from templates and data. Fast, secure, inexpensive to host and easy to scale. Well-known SSGs: Eleventy, Hugo, Astro, Next.js.
System Prompt
The system prompt is an overarching instruction that defines a language model's behavior for an entire conversation or application, such as its role, tone, rules and limits. Users usually don't see it, but it shapes every answer.

T

Target Audience Analysis
A systematic study of the demographic characteristics, needs, behaviors and motivations of the intended customer group. The foundation of every marketing strategy and every UX project.
Temperature (AI)
Temperature is a setting in language models that controls how random or creative the output is. Low values produce predictable, consistent answers; higher values produce more varied text.
Token
The basic processing unit of language models - usually parts of words or common character sequences. Costs, context windows and speed of LLM APIs are measured in tokens. In English, one token corresponds to roughly 4 characters.
TOMs (Technical and Organizational Measures)
TOMs are the safeguards for personal data required under Art. 32 GDPR, such as encryption, access controls, backups and training. They are documented and are regularly part of a data processing agreement.
Training Data
Training data is the body of data from which an AI model learns its abilities, such as text, images or code. Its quality, currency and origin largely determine the model's performance, possible biases and legal questions such as copyright.
Transformer Architecture
A neural network architecture with attention mechanisms (self-attention) introduced by Google researchers in 2017. The transformer architecture is the foundation of almost all modern LLMs, including the GPT, Claude, Gemini, Llama and Mistral model families.
Two-Factor Authentication (2FA)
Two-factor authentication secures accounts with a second, independent proof in addition to the password, such as a code from an authenticator app or a security key. 2FA prevents a large share of account takeovers caused by stolen passwords.
Typography
The art and technique of arranging type: choosing and using typefaces, font sizes, line spacing, letter spacing and hierarchies. Contributes significantly to readability and brand identity.

U

UI (User Interface)
The visual and interactive layer of an application that users come into direct contact with - buttons, forms, navigation, layouts, colors and typography.
Upscaling (AI)
AI upscaling enlarges images or videos and reconstructs missing details using trained models. This makes it possible, for example, to prepare older or low-resolution images for print and high-resolution screens.
URL Structure
The structure and organization of a website's web addresses. A clear, descriptive, hierarchical URL structure improves indexing by search engines and helps users find their way.
Usability
Usability describes how usable a website or application is, meaning how effectively, efficiently and satisfactorily users reach their goals. Good usability lowers bounce rates and increases the conversion rate.
UTM Parameters
UTM parameters are additions to a URL that let analytics tools attribute visitors to a campaign, channel or ad. They make the success of newsletters, social media posts and ads measurable.
UX (User Experience)
A user's overall experience when interacting with a product or website - from first impression through use to what happens afterward. Includes usability, accessibility, performance and emotional impact.

V

Vector Database
A specialized database that efficiently stores numerical vectors (embeddings) and enables semantic similarity searches. A central component of RAG systems. Examples: Pinecone, Weaviate, pgvector.
Version Control
A system for managing all changes to code, configurations or documents over time. Git is the de facto standard today - it enables traceability, collaboration and safe experimentation.
Vibe Coding
Vibe coding describes a way of working in which software is created mainly by giving AI tools instructions in natural language instead of writing the code yourself. It speeds up prototyping, but production applications require careful review of security and maintainability.
Voice Search
Voice search is searching by spoken input via smartphones, smart speakers or AI assistants. Voice queries are usually longer and phrased as questions, which is why clear, direct answers in content are becoming more important.

W

Watermarking (AI)
An AI watermark is a usually invisible marker in AI-generated text, images, audio or video files that makes their artificial origin machine-detectable. The EU AI Act requires providers of generative AI to ensure their output is identifiable as artificially generated in a machine-readable format.
WCAG (Web Content Accessibility Guidelines)
The WCAG are the W3C's internationally recognized guidelines for accessible web content, organized into the conformance levels A, AA and AAA. In practice, level AA is considered the benchmark for legal requirements such as the European Accessibility Act.
Web Vitals
Google's metrics for user-centered quality signals of a web page: loading (LCP), interactivity (INP) and visual stability (CLS). Poor Web Vitals can have a negative impact on Google rankings.
Webhook
A webhook is an automatic HTTP notification that one system sends to another as soon as a specific event occurs, such as a new order or a submitted form. Webhooks are a key building block for automations between web services.
Wireframe
A schematic sketch of the page structure and content hierarchy - without visual design, but with clear functionality, navigation and content areas. An important communication tool between UX, design and development.
WordPress
The most widely used content management system in the world - it powers more than 40% of all websites. Open source, hugely extensible through plugins, and suitable for everything from simple blogs to complex corporate websites.

X

XAI (Explainable AI)
Explainable AI (XAI) covers methods that make the decisions and results of AI systems understandable to people. XAI is important for trust, error analysis and regulatory requirements such as the transparency obligations of the EU AI Act.
XML
XML (Extensible Markup Language) is a text-based format for representing structured data and exchanging it between systems. On the web, XML is used for sitemaps, RSS feeds and e-invoices, for example.
XML Sitemap
A structured file in XML format that lists all important URLs of a website and makes it easier for search engine crawlers to index the site completely. Optionally contains metadata on change frequency and priority.
X-Robots-Tag
The X-Robots-Tag is an HTTP header that lets you set indexing instructions such as noindex or nofollow for any file, including PDFs or images without an HTML head. It complements robots.txt and meta robots tags.
XSS (Cross-Site Scripting)
Cross-site scripting is a security vulnerability in which attackers inject malicious JavaScript code into web pages, which is then executed in other users' browsers. Consistent input validation, output escaping and a Content Security Policy protect against it.

Y

YAML
YAML is an easy-to-read, text-based data format used mainly for configuration files, for example in CI/CD pipelines, Docker Compose or static site generators. The structure comes from indentation rather than brackets.
Yield Optimization
In online marketing, yield optimization means maximizing advertising revenue per available ad space, especially for publishers in programmatic advertising. Price floors, sales channels and placements are continuously adjusted based on data.
YMYL (Your Money or Your Life)
YMYL is a category from Google's Search Quality Rater Guidelines covering topics that can significantly affect people's health, finances, safety or well-being. YMYL content is held to especially high standards of expertise, authoritativeness and trustworthiness.
YOLO (You Only Look Once)
YOLO is a family of AI models for real-time object detection that locate and classify objects in images and videos in a single processing step. YOLO is used in quality control, logistics and video analytics, for example.
YouTube SEO
YouTube SEO covers measures that help videos get found more easily in YouTube search and recommendations, such as meaningful titles, descriptions, chapters, subtitles and thumbnails. Since YouTube content also appears in Google results and AI answers, YouTube SEO strengthens your overall visibility.

Z

Zero Trust
Zero trust is a security concept in which no user, device or service is automatically considered trustworthy, not even inside your own network. Every access is individually authenticated, authorized and limited to the minimum necessary rights.
Zero-Click Search
A zero-click search ends without the user clicking on a search result, because the answer already appears on the search results page or in an AI summary. For companies, being cited as a source in AI answers therefore becomes a visibility metric of its own.
Zero-Shot Prompting
A prompting technique in which a language model is asked to solve a task without any concrete examples - based only on its training data. By comparison, few-shot prompting provides a few examples for guidance.