Analytics & Tracking Glossary

A

Attribution

The process of assigning credit to marketing touchpoints that led to a conversion. Attribution models determine how credit is distributed—last-click gives all credit to the final touchpoint, while data-driven distributes credit based on actual impact.

Audiences

Groups of users defined by conditions you specify, used for analysis and remarketing. GA4 audiences can be based on demographics, behavior, or custom criteria. Audiences can be shared with Google Ads for targeted campaigns.

B

BigQuery Export

GA4's ability to export raw, hit-level data to Google BigQuery for advanced analysis. Unlike the GA4 interface which shows aggregated data, BigQuery export provides every event, enabling custom SQL queries and machine learning.

Bounce Rate

In Universal Analytics, the percentage of single-page sessions where users left without interaction. GA4 replaced this with Engagement Rate. A 'bounce' now means a session that wasn't engaged (under 10 seconds, no conversions, no additional pages).

C

CAPI (Conversions API)

Server-to-server integration that sends conversion data directly from your server to advertising platforms (Meta, TikTok, etc.). CAPI bypasses browser restrictions like ad blockers and iOS privacy changes, providing more reliable conversion tracking.

Click-Through Rate (CTR)

The percentage of people who click on a link or ad after seeing it. Calculated as clicks divided by impressions. Used to measure ad effectiveness and can indicate how compelling your messaging is.

Container

In GTM, a container holds all your tags, triggers, and variables for a specific website or app. Each container has a unique ID (GTM-XXXXXX) and generates a code snippet to install on your site.

Conversion

A valuable action a user takes on your website that you want to track, such as a purchase, form submission, sign-up, or phone call. Conversions are used to measure campaign effectiveness and optimize ad bidding.

Cross-Domain Tracking

Tracking users as they move between different domains you own (e.g., main site to checkout subdomain). Without proper setup, each domain looks like a new session, breaking analytics data and attribution.

Custom Dimensions

User-defined attributes in GA4 that let you collect and analyze data not captured by default. Examples include user type (logged in/guest), content category, or A/B test variant. Requires both GTM configuration and GA4 setup.

D

Data Layer

A JavaScript object (array) that temporarily holds data on your webpage before it's sent to GTM and other tools. The data layer provides a structured way to pass information like transaction details, user actions, and page data to your tracking tags.

Debug Mode

A testing state that sends events to GA4's DebugView in real-time. Enabled via GTM Preview Mode, the GA Debugger extension, or by adding debug_mode:true to your gtag config. Essential for verifying tracking before launch.

DebugView

A real-time debugging tool in GA4 that shows events as they're received. DebugView helps verify that tracking is working correctly by displaying event names, parameters, and user properties in near real-time.

E

Engagement Rate

GA4's replacement for bounce rate. The percentage of sessions that were 'engaged'—meaning they lasted longer than 10 seconds, had a conversion event, or had 2+ page/screen views. Higher is better (opposite of bounce rate).

Enhanced Conversions

A Google Ads feature that improves conversion measurement by sending hashed first-party customer data (email, phone) along with conversion tags. This helps recover conversions lost due to privacy restrictions and browser changes.

Enhanced Measurement

GA4's automatic tracking of common interactions without additional code. Includes page views, scrolls, outbound clicks, site search, video engagement, and file downloads. Can be toggled on/off in GA4 data stream settings.

Event

In GA4, an event is any user interaction or occurrence you want to measure. GA4 is entirely event-based—even pageviews are events. Events can have parameters that provide additional context (like transaction value).

Event Parameter

Additional data sent with a GA4 event to provide context. For example, a 'purchase' event might include parameters like transaction_id, value, currency, and items. Parameters enable detailed analysis beyond just event counts.

F

First-Party Cookies

Cookies set by the website domain you're visiting. These are more reliable than third-party cookies and aren't blocked by browsers. GA4 and GTM use first-party cookies for tracking, which is why server-side tracking can improve data accuracy.

G

GA4 (Google Analytics 4)

The current version of Google Analytics, replacing Universal Analytics (UA). GA4 uses an event-based data model rather than session-based, provides cross-platform tracking, and integrates machine learning for insights.

Google Tag Manager (GTM)

A free tag management system from Google that lets you deploy and manage marketing tags (code snippets) on your website without modifying the code directly. GTM acts as a container that holds all your tracking tags and controls when they fire.

L

Lookalike Audience

An advertising audience that resembles your existing customers. Platforms like Meta and Google analyze your customer list or website visitors to find new users with similar characteristics, expanding your reach to likely converters.

M

Measurement ID

The unique identifier for a GA4 data stream, formatted as 'G-XXXXXXXXXX'. This ID is used in your tracking code to send data to the correct GA4 property. Different from UA tracking IDs which start with 'UA-'.

Measurement Protocol

A way to send data directly to GA4 via HTTP requests, bypassing JavaScript. Used for server-side tracking, offline conversions, or IoT devices. Requires your Measurement ID and API secret.

P

Pixel

A small piece of JavaScript code placed on your website that tracks user behavior and sends data back to an advertising platform. Common pixels include Meta (Facebook) Pixel, TikTok Pixel, LinkedIn Insight Tag, and Pinterest Tag.

Preview Mode

GTM's testing environment that lets you see which tags fire on your website before publishing changes. Preview mode shows tag firing status, trigger conditions, and data layer values without affecting live tracking.

R

Referral Exclusions

Domains you tell GA4 to ignore as traffic sources. Used to prevent your own domains (payment processors, subdomains) from appearing as referrals and breaking session continuity during checkout flows.

Remarketing

Showing ads to users who have previously visited your website or taken specific actions. Remarketing requires a pixel or tag to build audience lists, which are then used for targeted advertising campaigns.

Return on Ad Spend (ROAS)

Revenue generated per dollar spent on advertising. A ROAS of 4:1 means you earned $4 for every $1 spent. Accurate ROAS requires proper conversion tracking with revenue values passed to ad platforms.

S

Server-Side GTM

A GTM setup where tags run on a server you control rather than in the user's browser. This improves data accuracy, bypasses ad blockers, enhances page speed, and provides better privacy compliance. Requires cloud hosting (typically Google Cloud or AWS).

Session

A group of user interactions with your website within a given time frame. In GA4, a session starts when a user opens your site and ends after 30 minutes of inactivity. Sessions help measure how often users return and how long they stay.

T

Tag

A piece of code that executes on your website, typically to send data to a third-party tool. Tags include analytics tracking (GA4), advertising pixels (Meta, Google Ads), and marketing tools (Hotjar, Intercom).

Third-Party Cookies

Cookies set by domains other than the one you're visiting (e.g., ad networks). Browsers increasingly block these for privacy. This is why advertisers are moving to first-party data and server-side tracking solutions.

Trigger

In GTM, a trigger defines when a tag should fire. Triggers can be based on page views, clicks, form submissions, custom events, or other conditions. A tag won't execute unless its trigger conditions are met.

U

Universal Analytics (UA)

The previous version of Google Analytics, which stopped processing data on July 1, 2023. UA used a session-based model and tracking IDs starting with 'UA-'. All websites should now use GA4 instead.

User Properties

Attributes that describe segments of your user base in GA4, such as language preference, membership level, or geographic location. Unlike event parameters, user properties persist across sessions.

UTM Parameters

Tags added to URLs to track campaign performance. The five standard UTMs are: source (where traffic comes from), medium (marketing channel), campaign (specific promotion), term (paid keywords), and content (ad variation).

V

Variable

In GTM, a variable is a named placeholder for a value that GTM can use. Variables can capture data layer values, URL parameters, cookie values, DOM elements, and more. They're used in triggers and tags.

A