SEO Glossary: 150+ Terms Defined in Plain English

Search engine optimization has its own vocabulary. If you have ever read an SEO audit or sat through a strategy call and felt lost, this glossary is for you.

Every term below is defined in practical, plain-English language. We have organized them alphabetically and tagged each entry by category so you can jump to the section most relevant to your business.

Use this page as a reference any time you encounter unfamiliar SEO terminology.

A

Above the Fold *(Content/UX)*

The portion of a web page visible without scrolling. Content placed above the fold gets seen first and typically receives the most engagement. Google considers above-the-fold content quality as a ranking signal.

Algorithm *(General SEO)*

A set of rules and calculations a search engine uses to determine which pages to show for a given query, and in what order. Google’s algorithm evaluates hundreds of ranking signals, from content relevance to page speed to backlink quality.

Alt Text (Alternative Text) *(Technical SEO)*

A text description added to an image’s HTML tag. Alt text helps screen readers describe images to visually impaired users and helps search engines understand image content. Write alt text that accurately describes the image and, where appropriate, includes relevant keywords.

Anchor Text *(Link Building)*

The clickable text within a hyperlink. Search engines use anchor text as a signal to understand what the linked page is about. Over-optimized anchor text (e.g., exact-match keyword phrases on every link) can trigger spam filters.

Authority *(General SEO)*

A measure of how trustworthy and credible a website or page is in Google’s evaluation. Authority is built through quality backlinks, brand mentions, consistent content publication, and user engagement signals.

B

Backlink *(Link Building)*

A link from another website pointing to your website. Backlinks remain one of the strongest ranking factors. Not all backlinks are equal — a link from a relevant, authoritative site carries far more weight than a link from a low-quality directory.

Black Hat SEO *(General SEO)*

SEO tactics that violate search engine guidelines. Examples include keyword stuffing, cloaking, paid link schemes, and hidden text. Black hat techniques may produce short-term gains but carry significant risk of penalties. Avoid them entirely.

Bounce Rate *(Analytics)*

The percentage of visitors who leave a website after viewing only one page. A high bounce rate may indicate poor content relevance, slow load times, or bad user experience. However, a high bounce rate is not always negative — a user who finds the answer they need on a single page may still be a satisfied visitor.

Branded Search *(General SEO)*

A search query that includes a specific business or brand name, such as “LocalCatalyst reviews” or “Nike running shoes.” Branded searches signal brand awareness and typically convert at higher rates than non-branded queries.

Breadcrumbs *(Technical SEO)*

A navigational element that shows users their location within a website’s hierarchy (e.g., Home > Services > Local SEO). Breadcrumbs improve user experience and help search engines understand site structure.

Broken Link *(Technical SEO)*

A hyperlink that points to a page that no longer exists, returning a 404 error. Broken links hurt user experience and can waste crawl budget. Regular link audits help identify and fix them.

C

Canonical Tag *(Technical SEO)*

An HTML element (`rel=”canonical”`) that tells search engines which version of a page is the primary version when duplicate or near-duplicate content exists. Proper canonicalization prevents duplicate content issues and consolidates ranking signals.

Citation *(Local SEO)*

Any online mention of a business’s name, address, and phone number (NAP). Citations appear on business directories, social media profiles, and industry-specific platforms. Consistent citations across the web strengthen local SEO performance.

Click-Through Rate (CTR) *(Analytics)*

The percentage of people who click on your listing after seeing it in search results. CTR is calculated by dividing clicks by impressions. Higher CTR signals to Google that your result is relevant and appealing to searchers.

Cloaking *(Black Hat)*

Showing different content to search engines than what human visitors see. Cloaking is a direct violation of Google’s guidelines and can result in manual penalties or deindexation.

Content Optimization *(Content)*

The process of improving existing content to rank better in search engines. This includes updating keyword targeting, improving readability, adding internal links, updating outdated information, and enhancing multimedia elements.

Core Web Vitals *(Technical SEO)*

A set of specific metrics Google uses to measure user experience on a page. The three Core Web Vitals are Largest Contentful Paint (LCP), which measures loading speed; Interaction to Next Paint (INP), which measures interactivity; and Cumulative Layout Shift (CLS), which measures visual stability. All three are confirmed ranking factors.

Crawl Budget *(Technical SEO)*

The number of pages a search engine bot will crawl on your site within a given timeframe. Large websites need to manage crawl budget carefully to ensure important pages get discovered and indexed.

Crawling *(Technical SEO)*

The process by which search engine bots discover web pages by following links and reading sitemaps. Crawling is the first step in getting a page indexed and ranked. See our guide to how Google Search works for a deeper explanation.

D

DA (Domain Authority) *(Link Building)*

A metric developed by Moz (not Google) that predicts how well a website will rank in search results on a scale of 1 to 100. DA is useful for competitive analysis but is not a Google ranking factor. Similar third-party metrics include Ahrefs’ Domain Rating (DR) and Majestic’s Trust Flow.

Disavow File *(Link Building)*

A file uploaded to Google Search Console that tells Google to ignore specific backlinks when evaluating your site. Used to combat negative SEO or to recover from link-based penalties.

Dofollow Link *(Link Building)*

A standard hyperlink that passes PageRank (link equity) from one page to another. Unless marked otherwise, all links are dofollow by default.

Domain Rating (DR) *(Link Building)*

A metric created by Ahrefs that measures the strength of a website’s backlink profile on a scale of 0 to 100. Like DA, DR is a third-party metric, not a Google ranking factor.

Duplicate Content *(Content/Technical SEO)*

Content that appears in more than one location online, either within the same site or across different sites. Duplicate content can confuse search engines about which version to rank. Canonical tags, 301 redirects, and unique content creation are the standard remedies.

E

E-E-A-T (Experience, Expertise, Authoritativeness, Trustworthiness) *(Content)*

A framework from Google’s Search Quality Evaluator Guidelines used to assess content quality. E-E-A-T is especially important for YMYL (Your Money or Your Life) topics. Pages that demonstrate firsthand experience, subject expertise, authority, and trustworthiness tend to rank higher.

Entity *(General SEO)*

A clearly defined concept, person, place, or thing that Google can understand and associate with related queries. Google’s Knowledge Graph is built on entities and their relationships. For local businesses, your Google Business Profile establishes your business as an entity.

External Link *(Link Building)*

A link from your website pointing to a page on a different domain. External links to authoritative sources can strengthen your content’s credibility and help search engines understand your topic.

F

Featured Snippet *(General SEO)*

A highlighted search result that appears at the top of Google’s organic results (position zero). Featured snippets pull content directly from a web page and display it in a box format. Formatting content with clear headings, lists, tables, and concise answers increases your chances of earning a featured snippet.

Fetch and Render *(Technical SEO)*

A tool within Google Search Console that allows you to see how Googlebot views and renders a specific page. Useful for diagnosing JavaScript rendering issues and ensuring Google can see all your content.

G

GBP (Google Business Profile) *(Local SEO)*

The free business listing that appears in Google Search and Google Maps. Previously called Google My Business (GMB). Your GBP is the most important asset in local SEO — it controls how your business appears in the Map Pack. Proper GBP optimization directly impacts local visibility.

Geotargeting *(Local SEO)*

The practice of delivering different content or results based on a user’s geographic location. In local SEO, geotargeting means optimizing content for specific cities, neighborhoods, or service areas.

Google Algorithm Update *(General SEO)*

A change to Google’s search algorithm that affects how pages are ranked. Major named updates include Panda, Penguin, Hummingbird, RankBrain, BERT, and the Helpful Content Update. Google also rolls out several core updates per year. See our complete guide to Google algorithm updates for a full timeline.

Google Maps Pack (Map Pack / Local Pack / 3-Pack) *(Local SEO)*

The section of Google search results that displays three local business listings alongside a map. Appearing in the Map Pack is critical for local businesses since it occupies prime real estate in search results and drives significant click-through traffic.

Google Search Console (GSC) *(Analytics/Technical SEO)*

A free Google tool that provides data about your website’s presence in Google search results. GSC shows which queries drive traffic, which pages are indexed, technical errors, Core Web Vitals performance, and manual actions.

Guest Posting *(Link Building)*

Writing and publishing content on another website, typically in exchange for a backlink to your own site. Guest posting remains a legitimate link building strategy when focused on relevant, authoritative publications with genuine editorial standards.

H

Header Tags (H1, H2, H3) *(On-Page SEO)*

HTML tags used to structure content hierarchically on a page. The H1 tag defines the main heading and should include the primary keyword. H2 and H3 tags organize supporting sections. Proper header structure helps both users and search engines understand content organization.

Hreflang *(Technical SEO)*

An HTML attribute that tells search engines which language and geographic region a page is intended for. Essential for multilingual and multi-regional websites to prevent duplicate content issues across language versions.

HTTPS *(Technical SEO)*

The secure version of HTTP, using SSL/TLS encryption to protect data between the browser and server. HTTPS has been a confirmed Google ranking signal since 2014. All websites should use HTTPS.

I

Impressions *(Analytics)*

The number of times a page from your website appears in search results, regardless of whether it was clicked. Impression data in Google Search Console reveals which queries your site is visible for.

Index / Indexing *(Technical SEO)*

The process of adding a web page to Google’s database (index) so it can appear in search results. A page must be crawled and indexed before it can rank. You can check indexing status in Google Search Console.

Internal Link *(On-Page SEO)*

A link from one page on your website to another page on the same website. Internal links distribute PageRank throughout your site, establish topical relationships between pages, and help users and search engines navigate your content.

J

JavaScript SEO *(Technical SEO)*

The practice of ensuring that content rendered by JavaScript is properly crawlable and indexable by search engines. While Google can render JavaScript, there are delays and limitations. Server-side rendering (SSR) or pre-rendering is often recommended for SEO-critical content.

JSON-LD *(Technical SEO)*

A format for implementing structured data (schema markup) on a web page. JSON-LD is Google’s preferred structured data format. It is added as a script block in the HTML head, making it easier to implement than inline markup alternatives.

K

Keyword *(General SEO)*

A word or phrase that users type into search engines. Keywords are the foundation of SEO strategy — they represent the queries you want your pages to appear for. Keyword research identifies the specific terms your target audience uses.

Keyword Cannibalization *(Content)*

A situation where multiple pages on the same website compete for the same keyword. Cannibalization dilutes ranking signals and can prevent any single page from ranking well. The fix typically involves consolidating content, adjusting keyword targeting, or using canonical tags.

Keyword Difficulty (KD) *(General SEO)*

A metric provided by SEO tools (Ahrefs, Semrush, Moz) that estimates how hard it would be to rank for a specific keyword. KD considers factors like the authority of currently ranking pages and the number of referring domains pointing to them.

Keyword Stuffing *(Black Hat)*

Overloading a page with keywords in an unnatural way to manipulate rankings. Keyword stuffing is a violation of Google’s guidelines and can result in ranking penalties. Write for humans first, then optimize naturally.

L

Landing Page *(Content/UX)*

A page designed with a specific goal in mind, usually conversion (lead form, phone call, purchase). In SEO, landing pages are optimized for specific keywords and user intents to drive organic traffic toward a conversion action.

Link Building *(Link Building)*

The process of acquiring backlinks from other websites to improve your site’s authority and rankings. Effective link building strategies include creating linkable content, guest posting, digital PR, local sponsorships, and resource outreach.

Link Equity (Link Juice) *(Link Building)*

The ranking value passed from one page to another through a hyperlink. Pages with more link equity tend to rank higher. Internal linking distributes link equity throughout your site.

Local Pack *(Local SEO)*

See “Google Maps Pack” above.

Local SEO *(Local SEO)*

The practice of optimizing a business’s online presence to attract more customers from local searches. Local SEO encompasses Google Business Profile optimization, local citation building, review management, localized content, and local link building. It is the core focus of what we do at LocalCatalyst.

Long-Tail Keyword *(General SEO)*

A longer, more specific search query, typically three or more words. Long-tail keywords have lower search volume but higher conversion rates and are usually easier to rank for. Example: “emergency plumber Austin TX” is a long-tail variant of “plumber Austin.”

LSI Keywords (Latent Semantic Indexing) *(Content)*

Conceptually related terms that help search engines understand the topic of a page. The term “LSI keywords” is technically a misnomer (Google does not use LSI specifically), but the concept of semantic relevance is valid. Including related terms naturally throughout content improves topical depth.

M

Manual Action *(General SEO)*

A penalty applied by a human reviewer at Google when a website violates Google’s webmaster guidelines. Manual actions appear in Google Search Console and can cause pages or entire sites to be demoted or removed from search results. They require a reconsideration request after fixing the violation.

Meta Description *(On-Page SEO)*

An HTML tag that provides a brief summary of a page’s content, typically displayed beneath the title in search results. While not a direct ranking factor, a compelling meta description improves click-through rate. Keep meta descriptions under 160 characters.

Meta Robots Tag *(Technical SEO)*

An HTML tag that instructs search engines on how to handle a specific page. Common directives include “noindex” (do not index this page), “nofollow” (do not follow links on this page), and “noarchive” (do not cache this page).

Mobile-First Indexing *(Technical SEO)*

Google’s approach of using the mobile version of a website as the primary version for indexing and ranking. Since the majority of searches occur on mobile devices, your mobile experience must be complete and performant.

N

NAP (Name, Address, Phone Number) *(Local SEO)*

The core business information that must be consistent across every online directory, citation source, and your own website. NAP inconsistency confuses search engines and weakens local rankings.

Nofollow *(Link Building)*

A link attribute (`rel=”nofollow”`) that tells search engines not to pass link equity through the link. Nofollow links are commonly used for sponsored content, user-generated content, and untrusted sources. Google treats nofollow as a “hint” rather than a directive.

Noindex *(Technical SEO)*

A meta robots directive that tells search engines not to include a specific page in their index. Use noindex for pages that should not appear in search results, such as thank-you pages, internal search results, or admin pages.

O

Off-Page SEO *(General SEO)*

SEO activities that occur outside your own website. Off-page SEO primarily involves link building, brand mentions, social signals, and reputation management. Off-page factors demonstrate to search engines that your website is authoritative and trusted by the broader web.

On-Page SEO *(On-Page SEO)*

The practice of optimizing individual web pages to rank higher. On-page SEO includes optimizing title tags, meta descriptions, header tags, content, images, internal links, URL structure, and schema markup.

Organic Search *(General SEO)*

Non-paid search results that appear based on relevance to the query, as determined by the search engine’s algorithm. Organic results appear below paid ads and, in local searches, below or alongside the Map Pack.

P

Page Speed *(Technical SEO)*

How quickly a web page loads and becomes interactive. Page speed is a confirmed ranking factor. Google’s PageSpeed Insights tool measures performance and provides optimization recommendations.

PageRank *(Link Building)*

Google’s original algorithm for measuring the importance of web pages based on the quantity and quality of links pointing to them. While Google no longer publicly shares PageRank scores, the underlying concept of link-based authority remains central to how rankings work.

PPC (Pay-Per-Click) *(Paid Search)*

An advertising model where advertisers pay each time a user clicks on their ad. Google Ads is the most common PPC platform. See our comparison of SEO vs PPC for guidance on when to use each approach.

Q

Query *(General SEO)*

The word or phrase a user types into a search engine. Understanding query intent (informational, navigational, commercial, transactional) is fundamental to creating content that ranks and satisfies users.

R

Ranking Factor *(General SEO)*

A signal or criterion that search engines use to determine where a page appears in search results. Google uses hundreds of ranking factors, including content relevance, backlinks, page speed, mobile-friendliness, user experience signals, and more.

Redirect (301 and 302) *(Technical SEO)*

A technique that sends users and search engines from one URL to another. A 301 redirect is permanent and passes link equity to the new URL. A 302 redirect is temporary and does not pass full link equity. Use 301 redirects when permanently moving or consolidating pages.

Referring Domain *(Link Building)*

A unique domain that links to your website. Having backlinks from a high number of unique referring domains is generally more valuable than having many links from a single domain.

Robots.txt *(Technical SEO)*

A text file placed in a website’s root directory that tells search engine crawlers which pages or sections of the site they are or are not allowed to crawl. Robots.txt does not prevent indexing — use noindex for that.

Rich Snippet *(Technical SEO)*

An enhanced search result that displays additional information beyond the standard title, URL, and meta description. Rich snippets can include star ratings, prices, FAQ dropdowns, recipe details, and more. They are generated through structured data markup.

S

Schema Markup (Structured Data) *(Technical SEO)*

Code added to a web page that helps search engines understand the content more precisely. Schema markup uses a standardized vocabulary (schema.org) to label entities like businesses, products, events, FAQs, and reviews. It enables rich snippets in search results.

Search Intent (User Intent) *(Content)*

The underlying goal behind a user’s search query. The four main types of search intent are informational (seeking knowledge), navigational (looking for a specific site), commercial (researching before a purchase), and transactional (ready to buy or take action). Aligning content with search intent is critical for ranking.

SERP (Search Engine Results Page) *(General SEO)*

The page displayed by a search engine in response to a query. Modern SERPs contain organic results, paid ads, featured snippets, knowledge panels, Map Packs, image results, video carousels, People Also Ask boxes, and more.

Sitemap (XML Sitemap) *(Technical SEO)*

An XML file that lists all the important pages on your website, helping search engines discover and crawl them efficiently. Submit your sitemap through Google Search Console. A well-structured sitemap is a basic requirement of technical SEO.

SSL Certificate *(Technical SEO)*

A digital certificate that authenticates a website’s identity and enables HTTPS encryption. An SSL certificate is required for HTTPS, which is a Google ranking factor.

T

Technical SEO *(Technical SEO)*

The process of optimizing the technical infrastructure of a website so search engines can crawl, index, and render it effectively. Technical SEO includes site speed optimization, mobile-friendliness, crawl error resolution, structured data implementation, HTTPS, XML sitemaps, and more.

Thin Content *(Content)*

Pages with little or no substantive content. Thin content provides minimal value to users and can result in lower rankings or manual actions. Examples include doorway pages, auto-generated content with no editorial oversight, and pages with only a few sentences.

Title Tag *(On-Page SEO)*

An HTML element that defines the title of a web page. Title tags appear as the clickable headline in search results and in browser tabs. They are one of the most important on-page ranking factors. Keep title tags under 60 characters and include the primary keyword.

Topical Authority *(Content)*

A website’s demonstrated expertise on a specific subject area, built through comprehensive, interlinked content covering all aspects of a topic. Sites with strong topical authority tend to rank more easily for related queries.

U

URL Structure *(Technical SEO)*

The format and organization of page URLs on a website. Clean, descriptive URLs that include relevant keywords are preferred over long, parameter-heavy URLs. Example of a good URL: `/services/` vs. a poor URL: `/page?id=4827&cat=3`.

User Experience (UX) *(General SEO)*

The overall experience a visitor has when interacting with a website. Google uses UX-related signals (Core Web Vitals, mobile-friendliness, HTTPS, non-intrusive interstitials) as ranking factors.

V

Visibility Score *(Analytics)*

A metric provided by SEO tools (Semrush, Sistrix) that measures the estimated organic visibility of a domain in search results. Visibility scores are useful for tracking overall SEO progress and benchmarking against competitors.

W

White Hat SEO *(General SEO)*

SEO practices that comply with search engine guidelines and focus on providing value to users. White hat SEO includes quality content creation, ethical link building, proper technical optimization, and honest representation. All long-term SEO strategies should be white hat.

X

XML Sitemap *(Technical SEO)*

See “Sitemap” above.

Y

YMYL (Your Money or Your Life) *(Content)*

A category of content defined by Google that can significantly impact a person’s financial stability, health, safety, or overall well-being. YMYL pages are held to higher E-E-A-T standards. Examples include medical advice, financial planning, legal information, and news content.

Z

Zero-Click Search *(General SEO)*

A search where the user finds the answer directly on the SERP without clicking through to any website. Featured snippets, knowledge panels, and direct answers contribute to zero-click searches. Optimizing for featured snippets can still build brand visibility even in zero-click scenarios.

Frequently Asked Questions

What is the most important SEO term to understand?

Search intent. Every other aspect of SEO — keyword research, content creation, link building, technical optimization — serves the goal of matching your pages to what users are actually looking for. If your content does not align with user intent, no amount of optimization will produce sustainable rankings.

What is the difference between on-page SEO and technical SEO?

On-page SEO refers to optimizing content-level elements like title tags, headings, keyword usage, and internal links. Technical SEO focuses on site infrastructure: crawlability, indexing, page speed, structured data, and mobile-friendliness. Both are necessary for a complete optimization strategy.

Do I need to memorize all these SEO terms?

No. Bookmark this page and use it as a reference. The terms you will encounter most frequently depend on where you are in your SEO journey. If you are focused on local visibility, start with the local SEO terms (GBP, NAP, citations, Map Pack). If you are fixing website issues, focus on the technical SEO terms.

How often does SEO terminology change?

The core concepts remain stable, but Google regularly introduces new features and metrics. For example, Core Web Vitals replaced older speed metrics, and E-E-A-T expanded from E-A-T. We update this glossary periodically to reflect the current SEO landscape.

Build Your SEO Vocabulary Into Action

Understanding SEO terminology is the first step. Turning that knowledge into a strategy that drives real business results is the next.

If you want a clear assessment of where your website stands and what it would take to improve your local search visibility, order an SEO audit(/services/seo-audit/). We will evaluate your site’s technical health, content quality, local presence, and competitive positioning — then give you a prioritized action plan.

No jargon without context. No recommendations without data.

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