Plain-English glossary

The web design + SEO glossary.

Plain-English definitions for the jargon you keep seeing in agency proposals. Bookmark this page and you'll never have to nod along again.

Analytics

LTV (Lifetime Value)

The total revenue a customer generates over their entire relationship with your business. The denominator of every marketing ROI calculation.

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CAC (Customer Acquisition Cost)

Total marketing + sales spend divided by new customers acquired. The numerator of every marketing ROI calculation.

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Churn Rate

The percentage of customers (or revenue) that stop doing business with you in a given period.

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Bounce Rate

The percentage of visitors who land on your site and leave without interacting. A high bounce rate often signals a relevance or quality problem.

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Dwell Time

How long a visitor stays on a page before bouncing or moving on. A signal Google uses to gauge content quality.

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Conversion

Conversion Rate

The percentage of visitors who complete a desired action — submitting a form, calling the phone number, booking a consult.

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Sticky CTA

A call-to-action element (typically a button or bar) that stays visible as the user scrolls. Especially powerful on mobile.

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Lead Magnet

A free piece of content (checklist, guide, template) offered in exchange for a visitor's email. Builds the top of your nurture funnel.

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Performance

INP (Interaction to Next Paint)

How long the page takes to visually respond to a user interaction (tap, click, keypress). Replaced FID as the official Core Web Vitals responsiveness metric in March 2024.

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TBT (Total Blocking Time)

Lab-data metric that sums all the time JavaScript blocked the main thread between First Contentful Paint and Time to Interactive.

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FID (First Input Delay)

Deprecated Core Web Vital that measured only the first user interaction. Replaced by INP in March 2024.

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Core Web Vitals

Google's three measurements of page experience — loading speed (LCP), interactivity (INP), and visual stability (CLS). A real ranking signal since 2024.

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LCP (Largest Contentful Paint)

How long it takes for the largest visible element (hero image, headline, etc.) to render. Google's primary loading-speed metric.

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CLS (Cumulative Layout Shift)

A measurement of how much elements on the page move around after the initial paint. Lower is better; a passing score is under 0.1.

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SEO

Local SEO

The practice of optimizing a website + Google Business Profile to rank for geographically-tied searches like '[service] near me' or '[service] [city].'

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Local Pack

The three business listings Google displays above the normal organic results for local searches, with a map. The most-clicked real estate in local search.

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Schema Markup

A vocabulary of structured data tags that tell Google what each piece of content on your page means — improving rich-result eligibility and AI citability.

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