Digital Glossary: Digital Marketing Acronyms You Need to Know
Digital Marketing · Glossary
SEO, AEO, GEO, Advertising, Analytics and AI
SEO, CPC, ROAS, CTR: Digital Marketing has always been a field full of acronyms. In recent years, however, its vocabulary has expanded rapidly with new terms related to artificial intelligence, generative search, measurement, privacy and even new ways of shopping online.
Alongside established concepts such as SEO, SEM, PPC and CTR, today marketing professionals increasingly encounter terms such as AEO, GEO, RAG, LLM, MMM, CDP, C2PA, ACP and UCP.
This is not simply a matter of terminology. The changing language reflects the evolution of digital marketing itself: people no longer discover products, services and brands exclusively through search engines, websites, social networks and advertising, but also through AI Overviews, answer engines, AI assistants and agents capable of taking actions and making purchases.
At the same time, privacy, first-party data and the growing difficulty of reconstructing the user’s complete journey have brought concepts such as incrementality, Marketing Mix Modeling, server-side tracking and Customer Lifetime Value back to the forefront.
We have therefore updated our glossary, bringing together the main terms and acronyms that are useful for navigating today’s Digital Marketing landscape.
01
Search & AI Search
From traditional search to answers generated by artificial intelligence.
SEO
Search Engine Optimization
Search
SEO encompasses the activities aimed at making a website understandable, accessible and relevant to search engines, improving its visibility in organic search results.
It includes technical aspects, information architecture, content, internal and external linking, structured data, performance and user experience. With the introduction of generative search experiences, SEO also remains one of the foundations through which search engine AI systems identify and retrieve information from the web.
SEM
Search Engine Marketing
Search
Historically, SEM refers to the full range of marketing activities carried out on search engines, including both SEO and advertising. In contemporary usage, however, the term is often used primarily to refer to paid advertising activities on search engines.
Search Engine Advertising
Advertising
SEA refers to paid advertising on search engines. It allows advertisers to display ads in relation to users’ searches, using auction-based systems and payment models primarily based on clicks or conversions.
Search Engine Results Page
Search
A SERP is the results page returned by a search engine. Today, it can include organic results, ads, maps, images, videos, featured snippets, shopping results and answers generated by artificial intelligence.
Answer Engine Optimization
AI Search
Answer Engine Optimization encompasses the activities aimed at making content and information easy to interpret and use by systems that provide direct answers to users’ questions.
The goal is not only to achieve a position in the SERP, but also to increase the likelihood that a piece of content can contribute to the answer provided by answer engines, AI assistants and generative search systems.
Generative Engine Optimization
AI Search
Generative Engine Optimization refers to activities aimed at increasing the visibility of a brand, a source or its content within search experiences based on generative artificial intelligence.
The focus therefore shifts from simply ranking a page to the ability of content to be discovered, interpreted, retrieved and used as a source by AI systems.
SEO, AEO and GEO should not, however, be considered three completely separate disciplines. Their techniques overlap and, for Google, optimization for its generative search experiences continues to be based on SEO best practices.
Large Language Model
Artificial Intelligence
A Large Language Model is an artificial intelligence model trained on large amounts of data and designed to process and generate language. LLMs are the foundation of many AI assistants and conversational search systems.
Retrieval-Augmented Generation
Artificial Intelligence
Retrieval-Augmented Generation combines the generation of a response by an AI model with the retrieval of information from external sources.
Before generating the response, the system searches for relevant information in documents, databases or web pages and uses it as context. It is one of the mechanisms that make it particularly important, including in AI Search, to produce content that is clear, reliable and easy to retrieve.
AI Overviews
Google Search
AI Overviews are answers generated by artificial intelligence that Google can display directly on the search results page, summarizing information from different sources and providing useful links for further exploration.
Zero-Click Search
Search
A Zero-Click Search is a search that ends without the user visiting an external result. The requested information is obtained directly from the SERP, an AI-generated answer, a map, a snippet or other search engine elements.
JavaScript Object Notation for Linked Data
Structured Data
JSON-LD is a format used to represent structured data and semantic relationships in a machine-readable way. On the web, it is commonly used to implement the Schema.org vocabulary.
02
Advertising & Performance
The metrics used to understand how much a campaign costs and how much it generates in return.
Pay Per Click
Advertising
An advertising model in which the advertiser pays when a user clicks on the ad.
Cost Per Click
Advertising
CPC represents the average cost incurred for each click received.
CPC = Cost / Clicks
Cost Per Mille
Advertising
It indicates the cost per thousand advertising impressions and is particularly used in campaigns focused on awareness and reach.
Click Through Rate
Performance
It measures the percentage of impressions that generate a click.
CTR = (Clicks / Impressions) × 100
Cost Per Acquisition
Performance
It indicates the average cost required to obtain an acquisition or a conversion defined as relevant to the business.
CPA = Cost / Acquisitions
Cost Per Lead
Lead Generation
It measures the average cost of generating a lead, for example a contact request or a form submission.
CPL = Cost / Leads
Conversion Rate
Performance
The Conversion Rate indicates the percentage of users who complete the action considered to be a conversion.
CVR = (Conversions / Users or sessions considered) × 100
Return on Advertising Spend
Performance
ROAS measures the ratio between the revenue attributed to an advertising campaign and the corresponding media investment.
ROAS = Attributed revenue / Advertising spend
It is a very useful metric, but it is not the same as profit: it does not necessarily take into account margins, operating costs, returns, logistics, consulting fees and other business costs.
Marketing Efficiency Ratio
Performance
The MER (Marketing Efficiency Ratio) measures the overall efficiency of marketing investment by comparing the total revenue generated by the company with its total marketing or advertising spend, depending on the scope used for the calculation.
MER = Total revenue / Marketing spend
Unlike ROAS, which attempts to measure the return attributed to a specific campaign, platform or advertising activity, MER looks at performance at a more aggregated level. For this reason, it is particularly widely used in ecommerce, where the purchase journey can involve multiple channels and attributing an individual conversion is becoming increasingly complex.
For example, if an ecommerce business generates €500,000 in revenue while investing a total of €100,000 in marketing, its MER is 5: for every euro invested, €5 in revenue is generated.
Return on Investment
Business
ROI measures the economic return of an investment in relation to the capital invested. Unlike ROAS, it considers the economic result of the investment rather than only the revenue attributed to media spend.
ROI = (Return − Investment) / Investment × 100
Call To Action
Conversion
It is an explicit invitation for the user to take an action: make a purchase, contact the company, sign up, download content or request information.
View Through Rate
Video Advertising
It measures the ratio between completed views of an advertising video and the impressions or views considered according to the definition used by the platform.
Share of Voice
Brand
It measures a brand’s share of visibility compared with its competitors within a specific market, channel or set of results.
Analytics & Measurement
Measurement is not just about counting clicks and conversions.
Key Performance Indicator
Measurement
KPIs are indicators used to measure progress towards an objective. Not all metrics are KPIs: a metric becomes a key performance indicator when it is directly linked to a decision or a business objective.
Bounce Rate
Analytics
In Google Analytics 4, Bounce Rate represents the percentage of sessions that are not considered engaged sessions and is therefore the inverse of Engagement Rate.
A session is considered engaged when it meets the criteria defined by GA4 relating to duration, key events or the number of views.
Engagement Rate
Analytics
In GA4, it represents the percentage of engaged sessions out of the total number of sessions. It is complementary to Bounce Rate.
Customer Acquisition Cost
Business
CAC measures the average cost of acquiring a new customer, taking into account the marketing and sales costs attributable to acquisition.
CAC = Acquisition costs / New customers
Customer Lifetime Value
Business
Customer Lifetime Value, also referred to as LTV, estimates the economic value generated by a customer throughout their entire relationship with the company.
Comparing CAC and CLV makes it possible to move beyond a view of performance limited to the individual conversion.
Marketing Mix Modeling
Measurement
Marketing Mix Modeling uses statistical models to estimate how different marketing and market factors contribute to business results.
Unlike attribution models based on an individual user’s journey, MMM works with aggregated data and can include online and offline advertising, promotions, seasonality, pricing and external variables.
Multi-Touch Attribution
Measurement
Multi-Touch Attribution attempts to distribute the value of a conversion across the different touchpoints encountered by the user throughout the customer journey.
The fragmentation of customer journeys, tracking limitations and privacy constraints, however, make it increasingly difficult to reconstruct individual behavior perfectly.
Incrementality
Measurement
Incrementality attempts to answer a different question from attribution: how many of the conversions observed were actually caused by the marketing activity, and how many would have occurred anyway?
Lift tests and controlled experiments are some of the tools used to estimate this incremental effect.
AdTech, Data & Privacy
The technologies that manage advertising, data, consent and audience activation.
Real-Time Bidding
Programmatic
A mechanism through which advertising impressions are bought and sold via automated auctions that take place in real time.
Demand-Side Platform
Programmatic
A platform used by advertisers to automatically purchase and optimize advertising inventory from different sources.
Supply-Side Platform
Programmatic
A platform used by publishers to make their advertising inventory available and automatically monetize it.
Data Management Platform
Data
A DMP collects and organizes audience data to create segments that can be used primarily for advertising.
Historically very important in programmatic advertising, its role has diminished with the evolution of privacy regulations, the progressive reduction of third-party identifiers and the growing importance of first-party data.
Customer Data Platform
Data
A Customer Data Platform collects and unifies first-party data from different touchpoints to build persistent customer profiles that can be used by marketing, analytics and other business systems.
Customer Relationship Management
Data
CRM refers to the processes and technologies used to manage relationships with prospects and customers, organizing information, sales opportunities, communications and sales activities.
Consent Management Platform
Privacy
A CMP is a platform used to collect, record and manage users’ consent preferences regarding cookies and other data processing technologies.
First-Party Data
Data
First-party data is data collected directly by a company through its own relationships and digital properties: website, ecommerce, CRM, apps, loyalty programs, customer service and other proprietary touchpoints.
Server-Side Tracking
Measurement
Server-side tracking moves part of the data collection and management process from the user’s browser to a server infrastructure controlled by the company.
It does not eliminate privacy and consent obligations, but it can increase control, governance and the quality of data flows.
AI, Content Provenance & Agentic Commerce
Emerging terms that are changing content, ecommerce and interactions between companies and AI agents.
Coalition for Content Provenance and Authenticity
Content Provenance
C2PA stands for the Coalition for Content Provenance and Authenticity and gives its name to an open technical standard for associating digital content with verifiable information about its provenance.
Through cryptographically signed manifests, information about the creation and modifications of content can be recorded, building a kind of digital passport for media.
C2PA does not determine whether content is true or false: it makes it possible to verify the integrity and provenance of the information declared in the manifest.
Model Context Protocol
AI & Agents
The Model Context Protocol (MCP) is an open standard that allows artificial intelligence applications to connect to external tools, data and services in a standardized way.
The goal is to avoid different proprietary integrations for every combination of AI model and external system. Through MCP, an AI application can, for example, access databases, documents, APIs and business tools using a common protocol.
MCP is therefore one of the elements of the emerging AI Agent infrastructure: it allows a model to go beyond the information available in its own context and interact with external resources and tools.
Agent2Agent Protocol
AI & Agents
A2A, Agent2Agent Protocol, is an open protocol designed to allow different artificial intelligence agents to communicate and collaborate with one another.
While MCP primarily facilitates connections between an AI application and tools or data sources, A2A addresses a different problem: enabling autonomous agents developed on different platforms to exchange information, coordinate activities and collaborate on the execution of a task.
It is an important concept in the evolution towards ecosystems in which there is not necessarily a single AI assistant, but rather multiple specialized agents cooperating with one another.
Agentic Commerce Protocol
Agentic Commerce
The Agentic Commerce Protocol is an open standard developed by OpenAI together with Stripe to enable AI agents and ecommerce systems to communicate throughout the purchasing process.
It enables operations such as checkout and payment to be managed in a standardized way while keeping the merchant responsible for the sale, order fulfillment and customer relationship.
ACP is the foundation of agentic commerce experiences designed to enable users to move from product discovery to transaction directly through an AI interface.
Universal Commerce Protocol
Agentic Commerce
The Universal Commerce Protocol is an open standard for agentic commerce developed by Google together with Shopify and other companies in the retail ecosystem.
The goal is to create a common language through which AI agents, merchants and payment systems can manage the entire commerce journey, from product discovery to checkout and post-purchase activities.
UCP can manage capabilities such as catalog, availability, pricing, cart, discounts, fulfillment and orders, avoiding the need for each merchant to build a completely different integration for every AI agent.
Agent Payments Protocol
Agentic Commerce
The Agent Payments Protocol (AP2) is an open protocol designed to enable payments made through artificial intelligence agents in an interoperable and verifiable way.
The issue becomes particularly important in agentic commerce: when an AI agent does not simply recommend a product but can participate in the transaction, it is necessary to establish what the user has authorized, which conditions must be met and how to demonstrate that the operation carried out by the agent corresponds to the user’s intentions.
AP2 therefore introduces mechanisms designed to create a verifiable relationship between the user, agent, merchant and payment systems.
It is part of the same ecosystem in which standards such as UCP and ACP are emerging, but specifically addresses the authorization and payment layer.
The glossary will continue to evolve
Digital Marketing has always been a field characterized by new tools and new acronyms, but the current evolution goes deeper: the very way in which people, platforms and companies find and exchange information is changing.
SEO, advertising and analytics remain fundamental, but today they coexist with generative search systems, more sophisticated attribution models, first-party data, content provenance standards and protocols that enable AI agents to interact directly with ecommerce platforms.
For this reason, knowing an acronym does not simply mean remembering what it stands for. It means understanding what problem it solves, which ecosystem it is used in and what impact it can have on marketing and business decisions.
Frequently asked questions about the Digital Marketing glossary
What is the difference between SEO, AEO and GEO?
SEO focuses on visibility in search engines, AEO on the ability to provide answers that can be easily used by answer engines, and GEO on visibility within search systems based on generative artificial intelligence. In practice, the three areas overlap significantly and share many best practices.
Will GEO replace SEO?
No. Generative search systems still use crawling, indexing, ranking and information retrieval infrastructures. For Google in particular, SEO best practices also remain the foundation for visibility within generative search experiences.
What is the difference between ROI and ROAS?
ROAS compares revenue attributed to advertising with advertising spend. ROI, on the other hand, measures the economic return on an investment by considering the result in relation to the costs incurred. A campaign can therefore have a high ROAS without necessarily being profitable.
What is the difference between CAC and CPA?
CPA measures the cost of a specific advertising acquisition or conversion, while CAC attempts to represent the overall cost required to acquire a new customer, including, depending on the model used, multiple marketing and sales components.
What are ACP and UCP?
ACP, Agentic Commerce Protocol, and UCP, Universal Commerce Protocol, are standards created to enable AI agents and ecommerce systems to communicate and manage commerce processes. ACP was developed by OpenAI with Stripe; UCP was developed by Google together with Shopify and other companies in the retail ecosystem.
What is C2PA used for?
C2PA makes it possible to associate digital content with verifiable information about its provenance and the transformations that have been made to it. It does not certify that content is true, but it makes it possible to verify the integrity of the declared provenance information.
Why have MMM and incrementality become more important?
Privacy, cross-device journeys, closed platforms and signal loss make it increasingly difficult to perfectly attribute every conversion to a single touchpoint. MMM, lift tests and incrementality analysis make it possible to evaluate marketing effectiveness using approaches that complement traditional individual-level attribution.
Sources and further reading
The definitions in this glossary have been updated with reference to the official documentation of the industry’s main standards and platforms.
Google Search Central
Optimization for generative AI features in Google Search
Official Google documentation on SEO, AEO, GEO, RAG and how generative search works.
Google / Universal Commerce Protocol
Universal Commerce Protocol
Documentation relating to the open UCP standard for agentic commerce.
OpenAI
Agentic Commerce Protocol
An introduction to Instant Checkout and the ACP standard developed for commerce through AI agents.
C2PA
Technical Specification
Official specifications for the standard covering the provenance and authenticity of digital content.
Google Analytics
Analytics Help
Official documentation covering engagement rate, bounce rate, events and GA4 metrics.
IAB
Digital Advertising Standards
Standards, definitions and best practices for digital advertising, programmatic advertising and measurement.
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