SEO Glossary

SEO comes with a lot of vocabulary, and most of it doesn’t need to be complicated. This glossary explains 127 SEO terms in plain English — the ones you’ll actually run into while working on a website, reading an SEO report, or trying to understand why your rankings changed. No unnecessary jargon, no assumed expertise. Use the letter index below to jump straight to a term, or scroll through and learn as you go.

3

301 Redirect

Technical SEO

A permanent redirect that sends visitors and search engines from an old URL to a new one, passing along most of its ranking value.

302 Redirect

Technical SEO

A temporary redirect that sends traffic to a different URL without permanently transferring the original page's ranking value.

4

404 Error

Technical SEO

The message shown when a requested page can't be found on the server, usually because it was moved or deleted without a redirect.

A

AI Crawler / Bot

Technical SEO

An automated program, like GPTBot or ClaudeBot, that visits websites to gather content used to train or power AI models and assistants.

AI Overview

AI Search & AEO

An AI-generated summary that Google shows at the top of some search results, answering the query before any regular links.

Algorithm

Fundamentals

The set of rules a search engine uses to decide which pages to show, and in what order, for a given search.

Alt Text

On-Page & Content

A short description added to an image so search engines and screen readers understand what it shows.

Anchor Text

On-Page & Content

The clickable, visible text of a link, which gives both users and search engines a clue about what the linked page is about.

Answer Engine Optimization (AEO)

AI Search & AEO

The practice of structuring content so AI-powered tools and chatbots can easily pull it out as a direct answer.

B

Off-Page & Link Building

A link from another website pointing to yours, which search engines often treat as a vote of confidence.

Tools & Analytics

A tool that shows which websites link to a given domain, and details about the quality of those links.

BERT

History & Updates

A 2019 Google update, based on a language model, that improved how the search engine understands context and natural phrasing in queries.

Black Hat SEO

Fundamentals

SEO techniques that try to trick search engines rather than genuinely improve a site, and that can get a site penalized.

Bounce Rate

On-Page & Content

The percentage of visitors who leave a page without interacting further or visiting another page on the site.

Brand Mention

Off-Page & Link Building

A reference to a brand or website online that doesn't necessarily include a clickable link.

Off-Page & Link Building

A link-earning tactic that involves finding dead links on other sites and suggesting your own content as a replacement.

C

Canonical Tag

On-Page & Content

A piece of code that tells search engines which version of a duplicate or similar page should be treated as the main one.

Citation (in AI Answers)

AI Search & AEO

A reference or link an AI assistant includes to show where a piece of information in its answer came from.

Content Cluster

On-Page & Content

A group of related articles linked together around one central topic, meant to show search engines that a site covers it thoroughly.

Content Marketing

On-Page & Content

Creating and sharing useful content — articles, videos, guides — to attract and engage an audience over time.

Conversion Rate

Tools & Analytics

The percentage of website visitors who complete a desired action, such as making a purchase or filling out a form.

Core Update

History & Updates

A broad, significant change to Google's ranking systems, released several times a year, that can shift rankings across many sites.

Core Web Vitals

Technical SEO

A set of Google metrics that measure a page's loading speed, responsiveness, and visual stability from a real user's perspective.

Crawl Budget

Technical SEO

The number of pages a search engine is willing to crawl on a site within a given time, which matters most for very large websites.

Crawl Error

Technical SEO

A problem that stops a search engine bot from properly accessing a page, such as a broken link or a server issue.

Crawling

Fundamentals

The process search engines use to discover pages on the web by following links from one page to another.

CTR (Click-Through Rate)

Tools & Analytics

The percentage of people who click a link after seeing it, out of everyone who saw it.

Cumulative Layout Shift (CLS)

Technical SEO

A Core Web Vitals metric measuring how much a page's layout unexpectedly shifts around while it's loading.

D

Digital PR

Off-Page & Link Building

Getting a brand covered by online publications and journalists, often as a way to earn high-quality backlinks and mentions.

Disavow File

Off-Page & Link Building

A list of backlinks submitted to Google asking it to ignore them when evaluating a site, usually to counter toxic links.

Dofollow

Technical SEO

A normal link with no restricting attribute, which allows ranking credit to pass from one page to another.

Domain Authority

Off-Page & Link Building

A third-party score that estimates how likely a whole website is to rank well, based mostly on its backlink profile.

Domain Rating / Authority Score

Tools & Analytics

A metric used by SEO tools to estimate a website's overall strength, usually based mainly on its backlink profile.

Duplicate Content

On-Page & Content

The same or very similar content appearing on more than one URL, which can confuse search engines about which page to rank.

E

E-E-A-T

On-Page & Content

Short for Experience, Expertise, Authoritativeness and Trustworthiness — the qualities Google looks for when judging how reliable content is.

Entity

AI Search & AEO

A specific, identifiable thing — a person, place, brand, or concept — that search engines and AI models can recognize and connect to other information.

Evergreen Content

On-Page & Content

Content that stays useful and accurate for a long time, without needing frequent updates.

F

SERP Features

A highlighted box near the top of Google's results that pulls a direct answer from a webpage to a specific question.

G

Generative Engine Optimization (GEO)

AI Search & AEO

Optimizing content so it's more likely to be referenced or cited by generative AI tools when they answer a question.

Google Analytics (GA4)

Tools & Analytics

A free Google tool that tracks how visitors behave on a website, such as which pages they view and how long they stay.

Google Business Profile

Local SEO

A free listing that lets a business manage how it appears on Google Search and Google Maps, including hours, photos, and reviews.

Google Hummingbird

History & Updates

A 2013 Google update that improved the search engine's ability to understand the meaning behind a full query, not just individual keywords.

Google Keyword Planner

Tools & Analytics

A free tool inside Google Ads that provides keyword ideas along with estimated search volume and cost-per-click data.

Google Map Pack

Local SEO

The block of 3 local business listings, with a map, that appears near the top of Google's results for local searches.

Google Panda

History & Updates

A 2011 Google update that targeted low-quality and thin content, rewarding sites with genuinely useful information.

Google Penguin

History & Updates

A 2012 Google update that targeted spammy and manipulative link-building practices.

Google Search Console

Tools & Analytics

A free Google tool that shows how a website performs in search, including clicks, impressions, and technical issues.

Guest Posting

Off-Page & Link Building

Writing an article for another website, usually including a link back to your own site, in exchange for exposure.

H

Header Tags (H1–H6)

On-Page & Content

HTML tags used to structure a page's headings, from the main title (H1) down to smaller subheadings.

Helpful Content Update

History & Updates

A Google update focused on rewarding content clearly written for people, and demoting content created mainly to rank in search.

Hreflang

Technical SEO

An HTML attribute that tells search engines which language and region a page is intended for, useful for multilingual sites.

HTTPS / SSL Certificate

Technical SEO

A security protocol that encrypts the connection between a browser and a website, shown by a padlock icon and 'https' in the address bar.

I

Impressions

Tools & Analytics

The number of times a page or link appeared in search results, whether or not it was clicked.

Indexing

Fundamentals

The step after crawling, where a search engine stores a page in its database so it can show it in results.

Interaction to Next Paint (INP)

Technical SEO

A Core Web Vitals metric measuring how quickly a page responds after a user clicks, taps, or types.

On-Page & Content

A link that connects one page of a website to another page on that same site.

J

JavaScript SEO

Technical SEO

The practice of making sure content built with JavaScript can still be properly crawled, rendered, and indexed by search engines.

K

Keyword

Fundamentals

A word or phrase people type into a search engine, and the term a page tries to rank for.

Keyword Cannibalization

On-Page & Content

When two or more pages on the same site compete for the same keyword, splitting ranking signals instead of combining them.

Keyword Density

On-Page & Content

How often a keyword appears on a page compared to the total word count, usually expressed as a percentage.

Keyword Research Tool

Tools & Analytics

Software that helps find search terms people use, along with estimated volume and competition data.

Keyword Stuffing

On-Page & Content

Repeating a keyword unnaturally often on a page in an attempt to rank higher, which search engines penalize.

Knowledge Panel

SERP Features

A box that appears on the side or top of Google results, summarizing facts about a person, place, or thing.

L

Large Language Model (LLM)

AI Search & AEO

An AI system trained on huge amounts of text, capable of understanding and generating human-like language, like the models behind ChatGPT or Claude.

Largest Contentful Paint (LCP)

Technical SEO

A Core Web Vitals metric measuring how long it takes for the largest visible piece of content on a page to load.

Off-Page & Link Building

The ongoing work of earning or acquiring backlinks from other websites to strengthen a site's authority.

Off-Page & Link Building

The informal term for the ranking value that passes from one page to another through a link.

llms.txt

AI Search & AEO

A proposed text file websites can add to give AI tools a clean, simplified summary of their content.

Local Citation

Local SEO

A mention of a business's name, address, and phone number on another website, such as an online directory.

Local Keyword Research

Local SEO

Finding the specific search terms people in a given area use when looking for a product or service.

Local Landing Page

Local SEO

A page created for a specific location a business serves, designed to rank for searches tied to that area.

Local SEO

Local SEO

The work of improving a business's visibility in local search results and map listings for people searching nearby.

Log File Analysis

Technical SEO

Reviewing a website's server logs to see exactly how search engine bots are crawling the site.

Long-Tail Keyword

Fundamentals

A longer, more specific search phrase with lower search volume but usually easier to rank for and more likely to convert.

M

Manual Action / Penalty

History & Updates

A penalty applied by a human reviewer at Google after a site is found to violate search guidelines, which can hurt or remove its rankings.

Meta Description

On-Page & Content

The short summary that appears under a page's title in search results, meant to convince someone to click.

Meta Keywords Tag

History & Updates

An old HTML tag once used to tell search engines what a page was about, largely abandoned after it was widely abused.

Mobile-First Indexing

Technical SEO

Google's approach of primarily using the mobile version of a page's content to decide how to rank and index it.

N

NAP Consistency

Local SEO

Making sure a business's Name, Address, and Phone number are written identically everywhere they appear online.

Natural Language Processing (NLP)

AI Search & AEO

The branch of AI focused on helping computers understand and work with human language, including how we phrase search queries.

Local SEO

A search that includes location intent, either explicitly ('coffee shop near me') or implied by the device's location.

Nofollow

Technical SEO

An attribute added to a link telling search engines not to pass ranking credit through it.

Noindex

Technical SEO

An instruction telling search engines not to include a specific page in their index, so it won't appear in search results.

O

Off-Page SEO

Off-Page & Link Building

Everything done outside a website to improve its reputation and rankings, mainly earning links and mentions from other sites.

On-Page SEO

On-Page & Content

Everything you optimize directly on a page — titles, headings, content, images — to help it rank and make sense to visitors.

Online Directory

Local SEO

A website that lists businesses along with details like their address, phone number, and reviews.

Fundamentals

Search results that appear because they're relevant, not because someone paid for them to be there.

Organic Traffic

Fundamentals

Visitors who arrive at a website by clicking an unpaid search result.

Orphan Page

Technical SEO

A page on a website that has no internal links pointing to it, making it hard for users and search engines to find.

P

Page Speed

Technical SEO

How quickly a webpage loads and becomes usable, which affects both user experience and rankings.

PageRank

History & Updates

Google's original algorithm for ranking pages, based on the idea that links from other pages act as votes of importance.

Pagination

Technical SEO

Splitting a long list of content across several numbered pages instead of showing it all on one page.

People Also Ask

SERP Features

A section in Google's results showing related questions that expand to reveal short answers when clicked.

Pillar Page

On-Page & Content

A broad, in-depth page that covers a topic at a high level and links out to more specific articles within a content cluster.

Position Zero

SERP Features

An informal name for the featured snippet spot, since it appears above the normal first organic result.

R

Rank Tracking

Tools & Analytics

Monitoring a website's position in search results for specific keywords over time.

Ranking Factor

Fundamentals

Anything a search engine considers when deciding how high a page should appear for a given search.

Readability Score

On-Page & Content

A score that estimates how easy a piece of text is to read, based on sentence length, word complexity, and similar factors.

Referring Domain

Off-Page & Link Building

A unique website that links to yours, counted once no matter how many individual links it contains.

Review Management

Local SEO

Monitoring, responding to, and encouraging customer reviews across platforms to maintain a good reputation.

Rich Snippet

SERP Features

A search result that shows extra details, like star ratings or prices, thanks to structured data added to the page.

Robots.txt

Technical SEO

A text file that tells search engine bots which parts of a website they're allowed or not allowed to crawl.

S

Search Engine

Fundamentals

A tool like Google or Bing that scans the web and shows you the pages that best match what you typed.

Search Intent

Fundamentals

The real reason behind a search — whether someone wants information, wants to buy something, or is looking for a specific website.

SEM (Search Engine Marketing)

Fundamentals

A broader term than SEO that covers both organic optimization and paid search ads, like Google Ads.

AI Search & AEO

A search approach focused on understanding the meaning and context behind a query, not just matching exact keywords.

SEO (Search Engine Optimization)

Fundamentals

The practice of improving a website so it shows up higher in unpaid search results, by working on its content, structure, and reputation.

SERP (Search Engine Results Page)

Fundamentals

The page you see after typing a search into Google, with links, ads, and other elements answering your query.

SERP Volatility

History & Updates

Noticeable ups and downs in search rankings, usually caused by a Google algorithm update rolling out.

Service Area Business (SAB)

Local SEO

A business that serves customers at their location rather than at a physical storefront, like a plumber or a delivery service.

Site Architecture

Technical SEO

How a website's pages are organized and linked together, which affects how easily users and search engines can navigate it.

Site Audit

Tools & Analytics

A review of a website's technical health and SEO setup that flags errors and opportunities for improvement.

SERP Features

Extra links to specific pages of a website that appear underneath its main search result.

Skyscraper Technique

Off-Page & Link Building

A content strategy that involves finding popular existing content, creating something noticeably better, and reaching out to sites that linked to the original.

Spam Update

History & Updates

A Google update focused specifically on detecting and reducing spammy content and manipulative SEO tactics.

Structured Data / Schema Markup

On-Page & Content

Extra code added to a page that describes its content in a standard format, helping search engines display it in richer ways.

Subdomain vs. Subfolder

Technical SEO

Two ways to organize a section of a website: a subdomain (blog.example.com) or a subfolder (example.com/blog), which can affect SEO differently.

T

Technical SEO

Technical SEO

Improvements made to a website's underlying structure and code so search engines can crawl, understand, and index it properly.

Thin Content

On-Page & Content

Pages with very little useful information, which tend to rank poorly because they don't fully answer what users are looking for.

Title Tag

On-Page & Content

The clickable headline that appears in search results and in the browser tab, defined in a page's HTML code.

Off-Page & Link Building

A low-quality or spammy link that can hurt a website's rankings rather than help them.

U

URL Slug

On-Page & Content

The part of a web address that comes after the domain name and identifies a specific page.

V

AI Search & AEO

Searching by speaking to a device instead of typing, often using more conversational, question-like phrasing.

W

Web Directory

History & Updates

An early way of organizing the internet where websites were manually reviewed and sorted into categories by human editors, like the old Yahoo Directory or DMOZ.

White Hat SEO

Fundamentals

SEO techniques that follow search engines' guidelines and focus on genuinely helping users.

X

XML Sitemap

Technical SEO

A file listing a website's important pages, submitted to search engines to help them find and understand the site's structure.

Z

SERP Features

A search where the user gets their answer directly on the results page and never clicks through to a website.

↑ Back to top

Scroll to Top