SEO Glossary: Comprehensive Guide to SEO Terms

Whether you're new to SEO or refining your strategy, this glossary breaks down key concepts, metrics, and tools across all major areas of search optimization.

Core SEO Concepts

SEO (Search Engine Optimization)

The practice of improving a website’s visibility in search engines to attract more organic traffic.

Organic Search

Traffic that comes from unpaid search results on Google or other search engines.

SERP (Search Engine Results Page)

The page users see after performing a search — includes organic results, paid ads, and featured snippets.

Search Intent

The goal behind a user’s search — informational, navigational, transactional, or commercial investigation.

Indexing

The process by which search engines store and organize website content to deliver in search results.

Crawling

When search engine bots scan webpages to discover and update content for indexing.

Sitemap

A file that lists all important URLs on a website, helping search engines crawl more efficiently.

Robots.txt

A file that tells search engine crawlers which pages or files they can or cannot access on your site.

Canonical URL

The preferred version of a webpage when duplicate or similar content exists across URLs.

On-Page SEO

Meta Tags

HTML elements providing metadata like title, description, and keywords for each page.

Title Tag

The page’s title shown in search results and browser tabs — a key on-page ranking factor.

Header Tags (H1–H6)

Used to structure content and signal topic hierarchy to both readers and search engines.

Internal Linking

Links connecting pages within your site to guide users and distribute ranking power.

Alt Text

Descriptive text for images that improves accessibility and helps search engines understand visuals.

URL Structure

Clean, descriptive URLs improve click-through rates and make pages easier to index.

E-E-A-T

A Google quality concept emphasizing Experience, Expertise, Authoritativeness, and Trustworthiness.

Featured Snippet

Highlighted answer box shown at the top of some Google results, pulled from a website’s content.

Off-Page SEO

Backlink

A link from another website pointing to your site — crucial for authority and rankings.

Domain Authority (DA)

A score (0–100) predicting how well a site will rank, influenced by backlinks and trust signals.

Anchor Text

The clickable text in a hyperlink that provides context to users and search engines.

Link Building

The process of earning quality backlinks from reputable websites to improve authority.

Nofollow / Dofollow Links

Attributes that tell search engines whether or not to pass ranking value through a link.

Referral Traffic

Visitors arriving at your site through external links from other domains.

Technical SEO

Technical SEO

Website optimizations that help search engines crawl, index, and render your pages efficiently.

Core Web Vitals

Google’s performance metrics that assess page speed, interactivity, and visual stability.

Mobile-Friendliness

A ranking factor based on how well your site performs on mobile devices.

HTTPS / SSL Certificate

A secure connection protocol that encrypts user data and signals site trustworthiness to Google.

Structured Data / Schema Markup

Code that helps search engines understand your content and display rich snippets in SERPs.

Redirects (301 / 302)

Used to send visitors and search engines from one URL to another. 301 = permanent; 302 = temporary.

Duplicate Content

Content that appears in multiple places on your site or across the web, which can confuse crawlers.

Canonical Tag

HTML tag that identifies the preferred version of a page to avoid duplicate content issues.

Local SEO

Google Business Profile (GBP)

A free business listing that helps your company appear in local search and map results.

NAP Consistency

Ensuring your Name, Address, and Phone number are identical across all directories and listings.

Local Citations

Mentions of your business information on other websites, directories, or platforms.

Map Pack

The set of three highlighted local business listings displayed in Google’s map results.

Local Keywords

Search terms that include geographic locations (e.g., “SEO consultant Toronto”).

Service Area Pages

Pages optimized for specific cities or regions to target local search visibility.

SEO Metrics & KPIs

Click-Through Rate (CTR)

Percentage of users who click your search result compared to how often it’s shown.

Conversion Rate

The percentage of visitors who complete a desired action — like filling a form or making a purchase.

Bounce Rate

The percentage of visitors who leave your site after viewing only one page.

Impressions

How many times your website or page appears in search results, regardless of clicks.

Organic Traffic

Visitors arriving through unpaid search engine results.

Keyword Ranking

Your position in search results for a given keyword — tracked over time to measure progress.

Keyword Research & Content Strategy

Keyword Difficulty

A metric showing how competitive a keyword is to rank for, based on authority and backlinks of top pages.

Search Volume

The average number of times a keyword is searched per month.

Long-Tail Keyword

A more specific, lower-competition keyword phrase that often converts better than broad terms.

Topic Cluster

A group of related content pages connected to a central pillar page to strengthen topical authority.

Content Gap

Missing topics or keywords your competitors rank for but you don’t — an opportunity to expand coverage.

SEO Tools & Platforms

Google Search Console

A free Google tool to track site performance, monitor indexing, and identify search issues.

Google Analytics

Tracks visitor behavior, traffic sources, and conversion data for your website.

Ahrefs

An advanced SEO toolset for backlink analysis, keyword research, and content audits.

SEMrush

A comprehensive SEO and PPC suite for competitive research, audits, and keyword tracking.

Screaming Frog

A website crawler used to identify technical SEO issues, broken links, and redirect chains.

Yoast SEO

A popular WordPress plugin that helps optimize on-page content and metadata.

Paid Search & SEM Terms

PPC (Pay-Per-Click)

An advertising model where you pay each time someone clicks on your ad.

CPC (Cost Per Click)

The amount paid per ad click — varies based on competition and keyword demand.

Quality Score

A Google Ads metric based on ad relevance, CTR, and landing page experience.

Ad Rank

Determines your ad’s position on a search results page — influenced by bid and quality score.

Impression Share

The percentage of times your ads are shown compared to the total available impressions.