60+ SEO Acronyms: The Complete A-Z Glossary

SEO and digital marketing are full of acronyms, and most guides throw them around as if everyone already knows them. This glossary is the plain-English version: every term that actually comes up in day-to-day search work, defined clearly and grouped alphabetically. Use the letter bar to jump to what you need, and follow the links to go deeper where we have a full guide.

A

AEO (Answer Engine Optimization). Optimizing content to be the direct answer in answer engines and AI results, such as featured snippets and AI Overviews. It overlaps heavily with SEO and GEO.

AMP (Accelerated Mobile Pages). An open-source framework for very fast mobile pages. Once heavily promoted by Google, now far less emphasized.

API (Application Programming Interface). A way for software to talk to other software. In SEO it is how tools pull data from sources like Search Console at scale.

AOV (Average Order Value). The average amount spent per order, a commerce metric that organic work often aims to lift.

B

B2B / B2C (Business-to-Business / Business-to-Consumer). Whether you sell to companies or to consumers. It shapes search intent, keywords and content.

BERT (Bidirectional Encoder Representations from Transformers). A Google language model rolled out in 2019 to better understand the intent behind queries.

C

CLS (Cumulative Layout Shift). A Core Web Vital measuring visual stability, how much the page jumps around as it loads.

CMS (Content Management System). Software for publishing and managing a site, such as WordPress.

CPC (Cost Per Click). What an advertiser pays per click in paid search, also used as a rough value proxy for a keyword.

CRO (Conversion Rate Optimization). Improving the share of visitors who take a desired action, like signing up or buying.

CTA (Call To Action). The prompt telling a visitor what to do next, for example “get the report”.

CTR (Click-Through Rate). The share of people who click your result after seeing it. It is heavily influenced by your title tag.

CWV (Core Web Vitals). Google’s set of real-user page-experience metrics: LCP, INP and CLS. Full guide: Core Web Vitals.

D

DA (Domain Authority). A third-party score from Moz that predicts ranking strength. Handy for comparison, but not a metric Google uses.

DR (Domain Rating). Ahrefs’ equivalent third-party authority score. Also not used by Google.

DNS (Domain Name System). The web’s address book, translating domain names into server IP addresses.

E

E-E-A-T (Experience, Expertise, Authoritativeness, Trust). The qualities Google’s quality raters use to judge content credibility, with Trust the most important. Full guide: E-E-A-T.

EMD (Exact Match Domain). A domain that is exactly the target keyword. Once a shortcut to rank, now largely neutralized.

F

FAQ (Frequently Asked Questions). A question-and-answer block, useful for covering sub-questions and matching how people phrase searches.

FID (First Input Delay). A former Core Web Vital for input responsiveness. It was replaced by INP in March 2024.

G

GA4 (Google Analytics 4). The current version of Google Analytics.

GBP (Google Business Profile). Your business listing on Google Maps and local results, formerly Google My Business.

GEO (Generative Engine Optimization). Optimizing to be cited inside AI-generated answers like ChatGPT and AI Overviews. Full guide: AEO vs GEO vs SEO.

GMB (Google My Business). The old name for Google Business Profile, renamed in 2021.

GSC (Google Search Console). Google’s free tool for monitoring how your site performs in Search. Full guide: Google Search Console.

GTM (Google Tag Manager). A tool for managing tracking tags without editing site code.

H

H1, H2, H3 (Heading tags). HTML tags that structure a page’s headings, from the main title (H1) down through subsections.

HTML (HyperText Markup Language). The code that structures web pages.

HTTPS (HyperText Transfer Protocol Secure). The encrypted version of HTTP, a lightweight ranking signal and a basic trust requirement.

I

IA (Information Architecture). How a site’s content is organized, grouped and linked.

INP (Interaction to Next Paint). The Core Web Vital for responsiveness that replaced FID in 2024.

IP (Internet Protocol) address. The numeric address of a server or device on a network.

J

JS (JavaScript). A language that adds interactivity. Content built with it must be rendered before search engines can see it, so keep your scripts crawlable. See technical SEO.

JSON-LD (JavaScript Object Notation for Linked Data). Google’s recommended format for adding structured data (schema) to a page.

K

KD (Keyword Difficulty). A tool’s estimate of how hard a keyword is to rank for, usually based on backlinks. Read it alongside the live results page, not on its own.

KPI (Key Performance Indicator). A metric you track to measure success, such as organic traffic, conversions or revenue.

L

LCP (Largest Contentful Paint). The Core Web Vital measuring how fast the main content loads.

LLM (Large Language Model). The AI behind tools like ChatGPT, Gemini and Claude that generate written answers. See what AI search is.

LSI (Latent Semantic Indexing). Often sold as “LSI keywords”, but Google has said it does not use LSI. Treat these simply as relevant, related terms, not a secret ranking system.

M

MFI (Mobile-First Indexing). Google predominantly uses the mobile version of your site for indexing and ranking. See technical SEO.

N

NAP (Name, Address, Phone). The core business details that must stay consistent across the web for local SEO.

O

OG (Open Graph). Meta tags that control how a page looks when it is shared on social platforms.

P

PA (Page Authority). Moz’s page-level authority score. Like DA, a third-party estimate, not a Google metric.

PBN (Private Blog Network). A network of sites built purely to pass links. It is a link scheme that violates Google’s guidelines.

PPC (Pay-Per-Click). Paid search advertising where you pay each time someone clicks your ad.

PR (PageRank). Google’s original link-based algorithm for scoring page importance. Also shorthand for (digital) PR.

Q

QDF (Query Deserves Freshness). The idea that some queries favor recent content, so Google surfaces fresher results for trending or time-sensitive searches. Relevant to content refreshes.

R

ROAS (Return On Ad Spend). Revenue earned per unit of advertising spend.

ROI (Return On Investment). The overall return relative to the cost of the work.

S

SEM (Search Engine Marketing). Marketing on search engines. Often used to mean paid search specifically, as opposed to organic SEO.

SEO (Search Engine Optimization). Improving a site so it earns more relevant organic, unpaid traffic from search. Start with how search engines actually work.

SERP (Search Engine Results Page). The page of results a search engine returns for a query.

SGE (Search Generative Experience). Google’s original name for its generative AI search. It is now delivered as AI Overviews and AI Mode.

SMM / SMO (Social Media Marketing / Optimization). Marketing on, and optimizing content for, social platforms.

SoV (Share of Voice). Your brand’s visibility across a set of queries or a market, relative to competitors.

SSL (Secure Sockets Layer). The technology behind HTTPS encryption (technically succeeded by TLS).

SSR (Server-Side Rendering). Rendering a page’s content on the server so crawlers and users receive full HTML. See technical SEO.

T

TF-IDF (Term Frequency-Inverse Document Frequency). A way of weighting how important a word is to a document, sometimes used in content analysis.

TLD (Top-Level Domain). The end of a domain, like .com or .org. Relevant to international SEO.

TTFB (Time To First Byte). How long the server takes to send the first byte of a response, an early page-speed signal.

U

UGC (User-Generated Content). Content created by users, like reviews and comments. Also a link attribute, rel ugc.

URL (Uniform Resource Locator). A web address.

UX / UI (User Experience / User Interface). How a site feels to use, and how it looks.

UTM (Urchin Tracking Module). Parameters added to a URL to track campaign sources in analytics.

V

VSO (Voice Search Optimization). Optimizing content for spoken queries through assistants like Siri, Alexa and Google Assistant, which tend to be longer and more conversational than typed searches.

W

WCAG (Web Content Accessibility Guidelines). The standards for making web content accessible to people with disabilities.

WWW (World Wide Web). The web itself, and the optional subdomain many sites still use.

X

XML (eXtensible Markup Language). The format used for sitemaps that list your URLs for search engines.

Y

YMYL (Your Money or Your Life). Topics that can affect a person’s health, finances or safety, which Google holds to the highest quality bar. See E-E-A-T.

Z

ZMOT (Zero Moment of Truth). A concept coined by Google for the online research moment when a person forms an opinion about a product before buying. It is exactly the moment strong SEO and content aim to win.

Frequently asked questions

What does SEO stand for?

SEO stands for Search Engine Optimization: the practice of improving a website so it earns more relevant organic (unpaid) traffic from search engines.

What is the difference between SEO and SEM?

SEO is about earning organic visibility. SEM (Search Engine Marketing) is the broader term for marketing on search engines, and in everyday use it usually refers to paid search (PPC) specifically. In short, SEO is unpaid, SEM commonly means paid.

What does SERP mean?

SERP stands for Search Engine Results Page, the page of results a search engine returns for a given query, including organic listings, ads and features like snippets and AI Overviews.

Are DA and DR official Google ranking metrics?

No. Domain Authority (Moz) and Domain Rating (Ahrefs) are useful third-party scores for comparing sites, but Google does not use either one to rank pages.

Written by Matthis Duarte, a senior SEO and organic growth expert with 10+ years of experience driving organic growth for international brands across highly competitive verticals. He is the founder of Knownful, an independent publication on SEO and organic growth featuring in-depth guides, best practices, playbooks and original analyses, including a free monthly study of which brands AI actually recommends across 10 industries.