Glossary and Key Terms
Below is a collection of key terms featured throughout our AdTech & Programmatic Advertising Book.
Ad blocker
A browser extension or application that prevents advertisements from being served and displayed on web pages by blocking requests to ad servers or hiding ad elements.
Ad exchange
A digital marketplace that enables advertisers and publishers to buy and sell advertising space through real-time auctions. Ad exchanges connect demand-side platforms (DSPs) with supply-side platforms (SSPs).
Ad network
An advertising platform that acts as an intermediary, connecting advertisers with publishers by aggregating ad inventory from multiple websites and selling it to advertisers, often in bulk.
Ad server
A web server that stores, manages, delivers, and tracks digital advertisements. Both advertisers (third-party) and publishers (first-party) use ad servers to manage and measure campaigns.
Ad slot
The specific technical container on a webpage or app into which an ad creative is delivered at a given moment. A single page can have multiple ad slots.
Ad space
A part of a web page or app screen that has been reserved by a publisher for advertising.
Ad tag
A snippet of code (typically JavaScript or HTML) that a publisher places on their website to call an ad server and display an advertisement.
AdTech (advertising technology)
The umbrella term for the software and tools that advertisers, agencies, and publishers use to target, deliver, and measure their digital advertising efforts.
Agency trading desk (ATD)
A specialised, in-house unit within an advertising agency that manages programmatic ad buying for its clients, typically by operating a demand-side platform (DSP).
Attribution
The process of assigning credit for a desired outcome (like a conversion) to the various advertising touchpoints a user was exposed to along their journey.
Click-through rate (CTR)
The percentage of ad impressions that result in a user clicking on the ad, calculated as (Clicks ÷ Impressions) × 100. It is a primary measure of ad engagement.
Connected TV (CTV)
Television sets connected to the internet, allowing for the streaming of video content. CTV advertising refers to ads delivered within this streaming environment.
Cookie
A small text file stored on a user’s device by a website. First-party cookies are set by the domain the user is visiting. Third-party cookies are set by a different domain, often for cross-site tracking.
Cookie syncing
The process of matching a user’s cookie ID between different AdTech platforms (e.g., between a DSP and an SSP) to recognise the same user across different domains.
Cost per action/acquisition (CPA)
A pricing model where an advertiser pays only when a user completes a specific, desired action, such as a purchase, sign-up, or form submission.
Cost per click (CPC)
A pricing model where an advertiser pays each time a user clicks on their ad.
Cost per mille (CPM)
A pricing model where an advertiser pays a set price for one thousand ad impressions (views). “Mille” is Latin for thousand.
Creative
The actual ad displayed to a user. This can be an image, video, audio file, text, or any multimedia object that constitutes the advertisement.
Customer data platform (CDP)
A software platform that creates a persistent, unified customer database by collecting and integrating first-party data from multiple sources (e.g., CRM, website, mobile app) to create a single customer view.
Data clean room
A secure, privacy-preserving environment where two or more parties can collaborate on their datasets (e.g., for attribution) without sharing the raw, underlying data with each other.
Data management platform (DMP)
A centralised platform that collects, organises, and activates large amounts of primarily anonymous audience data (often from third-party cookies) to create segments for ad targeting.
Demand-side platform (DSP)
An advertising platform that allows advertisers and agencies to buy ad inventory from multiple sources (ad exchanges, SSPs) through a single interface, typically via real-time bidding.
Device fingerprinting
A tracking technique that creates a unique identifier for a device by collecting information about its specific configuration (e.g., browser version, installed fonts, screen resolution) without using cookies.
Digital advertising
The practice of delivering promotional content to users through various online and digital channels, such as websites, social media, search engines, mobile apps, and streaming services.
Digital out-of-home (DOOH)
Digital screens in public spaces, such as billboards and transit displays, that are connected to the internet and can be bought and managed programmatically.
Dynamic creative optimisation (DCO)
A technology that automatically generates personalised ad creatives in real-time by assembling different components (e.g., images, text, CTAs) based on data about the user, such as location, behaviour, or weather.
First-party data
Data that a company collects directly from its own customers or audience with their consent (e.g., from website visits, CRM systems, or purchases).
Frequency capping
The practice of setting a limit on the number of times a specific ad is shown to a single user within a given timeframe to prevent ad fatigue and wasted impressions.
GDPR (General Data Protection Regulation)
A landmark data privacy and protection regulation in the European Union that governs how companies must handle the “personal data” of EU residents.
Header bidding
A programmatic technique that allows publishers to offer their ad inventory to multiple ad exchanges simultaneously before making a call to their ad server, increasing competition and revenue.
Impression
A single instance of an ad being displayed on a web page or in an app. It is the most basic unit of ad inventory.
Insertion order (IO)
A formal, contractual document used in traditional and direct ad buying that specifies the details of a campaign, such as dates, ad sizes, placements, and pricing.
Interactive Advertising Bureau (IAB)
A global trade organisation that develops technical standards, conducts research, and provides legal support for the online advertising industry. It sets standards for ad formats and measurement.
MadTech
A term that refers to the convergence of advertising technology (AdTech) and marketing technology (MarTech), reflecting the increasing integration of paid media and owned marketing channels.
Marketing technology (MarTech)
Software used by marketing teams to plan, execute, manage, and measure their marketing campaigns and activities across owned channels (e.g., email, social media, website).
Marketing mix modelling (MMM)
A top-down statistical analysis that measures the impact of various marketing activities on sales, while also accounting for non-marketing factors like seasonality and economic trends.
Measurement
The process of collecting, aggregating, and reporting on advertising campaign data to quantify performance using key metrics like impressions, clicks, and conversions.
Multi-touch attribution (MTA)
An attribution approach that evaluates the impact of every touchpoint a consumer is exposed to on their path to conversion, assigning fractional credit to each interaction.
Native ads
Paid advertisements that are designed to match the form, feel, and function of the content on the platform where they appear, making them less intrusive than traditional banner ads.
Online advertising
A broad term for advertising that uses the internet to deliver marketing messages to consumers. It is largely synonymous with digital advertising.
Private marketplace (PMP)
An invitation-only version of real-time bidding (RTB) where a publisher makes its premium ad inventory available to a select group of advertisers.
Programmatic advertising
The use of data, software, and automation to buy, sell, deliver, and measure digital advertising in real-time.
Publisher
An individual or company that owns and operates a website, mobile app, or other digital property and makes its ad inventory available for advertisers to purchase.
Real-time bidding (RTB)
An auction-based process where digital ad impressions are bought and sold in real-time, one at a time. The entire transaction, from bid request to ad serving, happens in milliseconds.
Rich media
Advanced ad formats that include interactive elements, animations, video, or other features that encourage user engagement beyond a simple click.
Supply-side platform (SSP)
A platform that allows publishers to manage, sell, and optimise their ad inventory programmatically. SSPs connect publisher inventory to multiple ad exchanges and DSPs.
Third-party data
Data collected by an entity that does not have a direct relationship with the user. It is often aggregated from multiple sources and sold to advertisers for targeting purposes.
Universal ID
An identifier that aims to replace the third-party cookie by creating a shared, privacy-compliant ID for recognising users across the open web, typically based on first-party, authenticated data like a hashed email.
User-agent string
A User-Agent (UA) string is a line of text a web browser or other client software sends to a web server with every request. It acts as a digital introduction, identifying the browser, its rendering engine, the operating system, and often the device type.
VAST (video ad serving template)
An XML-based script developed by the IAB that provides a standard for communication between video players and ad servers to ensure video ads are delivered and measured consistently.
Viewability
A metric that tracks whether an ad had an opportunity to be seen by a user. The IAB standard is 50% of the ad’s pixels in view for at least one second (two seconds for video).
Walled garden
A closed digital ecosystem, such as those operated by Google, Meta, and Amazon, where the platform controls both the advertising and the user data, limiting access for independent third-party measurement.