# Datacenter analytics glossary

> 68 web analytics, attribution and ad tracking terms, each defined in plain words.

Source: https://datacenter.so/glossary

- [Ad blocker](https://datacenter.so/glossary/ad-blocker.md): Browser software that blocks ads and, often, the tracking scripts and pixels that measure them.
- [ARR](https://datacenter.so/glossary/arr.md): Annual recurring revenue: the yearly run rate of active subscriptions, usually MRR × 12.
- [Attribution](https://datacenter.so/glossary/attribution.md): The rule that decides which marketing touch gets credit for a sale, signup or other conversion.
- [Attribution window](https://datacenter.so/glossary/attribution-window.md): How long after a click or view a conversion can still be credited to it.
- [Blended ROAS](https://datacenter.so/glossary/blended-roas.md): Total revenue from your store divided by total ad spend on every platform, for the same period.
- [Bot traffic](https://datacenter.so/glossary/bot-traffic.md): Visits made by automated software rather than people: crawlers, scrapers, monitors and fake clicks.
- [Bounce rate](https://datacenter.so/glossary/bounce-rate.md): The share of visits or sessions that ended without engagement; each tool defines it differently.
- [Break-even ROAS](https://datacenter.so/glossary/break-even-roas.md): The ROAS at which ad revenue exactly covers the ad spend and the cost of the goods sold: 1 ÷ gross margin.
- [Call tracking](https://datacenter.so/glossary/call-tracking.md): Crediting phone calls to their source by giving each ad, place or website visitor its own forwarding number.
- [Churn](https://datacenter.so/glossary/churn.md): The share of paying customers, or of recurring revenue, that stops in a period.
- [Click ID](https://datacenter.so/glossary/click-id.md): A unique value an ad platform adds to the link when someone clicks an ad, so it can match later conversions to that click.
- [Consent banner](https://datacenter.so/glossary/consent-banner.md): The notice that asks visitors to accept or decline cookies and similar tracking on a website.
- [Consent mode](https://datacenter.so/glossary/consent-mode.md): Google's way for its tags to change behavior based on the visitor's consent choices.
- [Conversion](https://datacenter.so/glossary/conversion.md): An action you count as success: a purchase, a signup, a booked call, a form sent.
- [Conversion rate](https://datacenter.so/glossary/conversion-rate.md): The share of visits, sessions or users that converted.
- [Conversion window](https://datacenter.so/glossary/conversion-window.md): The Google Ads setting for how long after an ad interaction a conversion can be recorded.
- [Conversions API](https://datacenter.so/glossary/conversions-api.md): Meta's server-to-server interface for sending conversion events, alongside or instead of the pixel.
- [Cookieless tracking](https://datacenter.so/glossary/cookieless-tracking.md): Measuring visits without storing cookies or other data on the visitor's device.
- [Cost per lead](https://datacenter.so/glossary/cost-per-lead.md): Ad spend divided by the number of leads it brought, for the same period and campaigns.
- [CPA](https://datacenter.so/glossary/cpa.md): Cost per acquisition: ad spend divided by the number of conversions.
- [Dark social](https://datacenter.so/glossary/dark-social.md): Shares through private channels, such as messaging apps and email, that arrive without a referrer.
- [Data thresholds](https://datacenter.so/glossary/data-thresholds.md): GA4 rules that withhold small rows of data so individual users cannot be identified.
- [Data-driven attribution](https://datacenter.so/glossary/data-driven-attribution.md): A model that learns how to split credit from your own conversion paths, instead of a fixed rule.
- [Direct traffic](https://datacenter.so/glossary/direct-traffic.md): Visits that arrived with no referrer, no campaign tags and no click id, so the tool cannot tell where they came from.
- [Dynamic number insertion](https://datacenter.so/glossary/dni.md): A script that shows each website visitor their own tracking number, so a call can be tied to the visit.
- [Engagement rate](https://datacenter.so/glossary/engagement-rate.md): In GA4, the share of sessions that were engaged.
- [Enhanced conversions](https://datacenter.so/glossary/enhanced-conversions.md): Google Ads' feature that sends hashed customer details with conversions to improve matching.
- [Event deduplication](https://datacenter.so/glossary/event-deduplication.md): Merging the same conversion reported twice, such as by the browser and the server, so it counts once.
- [Event Match Quality](https://datacenter.so/glossary/event-match-quality.md): Meta's score for how well the customer details on your server events can be matched to Meta accounts.
- [Exit rate](https://datacenter.so/glossary/exit-rate.md): The share of a page's views that were the last in their visit.
- [fbclid](https://datacenter.so/glossary/fbclid.md): Meta's click id, added to links people click on Facebook and Instagram.
- [First-party cookie](https://datacenter.so/glossary/first-party-cookie.md): A cookie set by the site the visitor is on, readable only by that site.
- [First-touch attribution](https://datacenter.so/glossary/first-touch-attribution.md): A model that gives all the credit for a conversion to the first known touch.
- [gclid](https://datacenter.so/glossary/gclid.md): Google Ads' click id, added to landing page links by auto-tagging.
- [Global Privacy Control](https://datacenter.so/glossary/global-privacy-control.md): A browser signal asking websites not to sell or share the visitor's personal data.
- [Incrementality](https://datacenter.so/glossary/incrementality.md): The conversions an ad caused that would not have happened without it.
- [Intelligent Tracking Prevention](https://datacenter.so/glossary/itp.md): Safari's set of limits on cookies and storage used for tracking.
- [Key event](https://datacenter.so/glossary/key-event.md): GA4's name for an event you mark as important to your business, such as a purchase, a signup or a booked call.
- [Landing page](https://datacenter.so/glossary/landing-page.md): The first page a visitor sees in a visit, or a page built for one campaign.
- [Landing page experience](https://datacenter.so/glossary/landing-page-experience.md): Google Ads' estimate of how relevant and useful a landing page is for the people who click an ad.
- [Last-touch attribution](https://datacenter.so/glossary/last-touch-attribution.md): A model that gives all the credit for a conversion to the final touch before it.
- [Lifetime value](https://datacenter.so/glossary/ltv.md): The total revenue, or profit, a customer brings over their whole relationship with you.
- [Lift test](https://datacenter.so/glossary/lift-test.md): An experiment that compares people who saw ads with a held-back group to measure the ads' real effect.
- [Marketing mix model](https://datacenter.so/glossary/marketing-mix-model.md): A statistical model that estimates each channel's effect on sales from aggregate spend and sales over time.
- [MER](https://datacenter.so/glossary/mer.md): Marketing efficiency ratio: total revenue divided by total marketing spend.
- [MRR](https://datacenter.so/glossary/mrr.md): Monthly recurring revenue: the monthly value of every subscription that is paying now.
- [Multi-touch attribution](https://datacenter.so/glossary/multi-touch-attribution.md): Any attribution model that splits credit across more than one touch.
- [Pageview](https://datacenter.so/glossary/pageview.md): One page loaded and counted by an analytics tool.
- [QR code](https://datacenter.so/glossary/qr-code.md): A square barcode that phones read with the camera to open a link.
- [Referrer](https://datacenter.so/glossary/referrer.md): The address of the page a visitor came from, sent by the browser when they follow a link.
- [Retention rate](https://datacenter.so/glossary/retention-rate.md): The share of customers, or of recurring revenue, still with you at the end of a period.
- [ROAS](https://datacenter.so/glossary/roas.md): Return on ad spend: revenue credited to ads divided by what the ads cost.
- [Sampling](https://datacenter.so/glossary/sampling.md): Building a report from a portion of the data and scaling the result up to estimate the whole.
- [Server-side tagging](https://datacenter.so/glossary/server-side-tagging.md): Running marketing and analytics tags on a server you control, which then forwards data to each vendor.
- [Server-side tracking](https://datacenter.so/glossary/server-side-tracking.md): Sending analytics or conversion events from a server, rather than from the visitor's browser.
- [Session](https://datacenter.so/glossary/session.md): A group of pageviews and events from one browser, ended by a period of inactivity or another rule.
- [Session timeout](https://datacenter.so/glossary/session-timeout.md): How long a visitor can be inactive before their session ends and the next action starts a new one.
- [Short link](https://datacenter.so/glossary/short-link.md): A short address on a link domain that redirects to a longer one, counting the click on the way.
- [Third-party cookie](https://datacenter.so/glossary/third-party-cookie.md): A cookie set by a domain other than the one in the address bar, used to follow people across sites.
- [Unique visitor](https://datacenter.so/glossary/unique-visitor.md): A browser or person counted once in a period, however many times they visited.
- [UTM parameters](https://datacenter.so/glossary/utm-parameters.md): Tags added to the end of a link that tell analytics tools the source, medium and campaign of the visit.
- [utm_campaign](https://datacenter.so/glossary/utm-campaign.md): The UTM parameter that names the specific push, offer or promotion a link belongs to.
- [utm_content](https://datacenter.so/glossary/utm-content.md): The UTM parameter that tells apart links or creatives within the same campaign.
- [utm_medium](https://datacenter.so/glossary/utm-medium.md): The UTM parameter that names the kind of channel: social, cpc, email, sms, qr.
- [utm_source](https://datacenter.so/glossary/utm-source.md): The UTM parameter that names who sent the visit: a site, app, newsletter or partner.
- [utm_term](https://datacenter.so/glossary/utm-term.md): The UTM parameter originally made for the paid search keyword, often used for the ad set or audience.
- [View-through conversion](https://datacenter.so/glossary/view-through-conversion.md): A conversion credited to an ad the person saw but did not click.
- [Year over year](https://datacenter.so/glossary/year-over-year.md): A comparison of a period with the same period a year earlier, to see growth after seasonality.