SEO SchoolLevel 1: SEO FundamentalsLesson 9
Level 1: SEO Fundamentals
Lesson 9/10
15 min read
2026-01-03

The SEO Glossary: 50 Terms You Must Know

Master SEO terminology with this comprehensive glossary of 50 essential terms covering fundamentals, on-page, off-page, technical SEO, and analytics.

The world of SEO has its own language. To navigate the industry professionally, you need to speak the dialect. This glossary covers 50 essential terms, categorized by their function.

I. The Fundamentals (General Concepts)

  • Algorithm: The complex computer program search engines use to retrieve data and deliver accurate results for a query.
  • Black Hat SEO: Unethical SEO practices that violate search engine guidelines (e.g., keyword stuffing, cloaking).
  • Bot (Crawler/Spider): Automated software (like Googlebot) that browses the web to index content.
  • Cloaking: Showing different content to search engines than what is shown to human users (a Black Hat tactic).
  • Conversion: When a user completes a desired action (e.g., buying a product, signing up for a newsletter).
  • E-E-A-T: Google's quality framework: Experience, Expertise, Authoritativeness, and Trustworthiness.
  • Index: The database where search engines store all the web pages they have crawled.
  • Keyword: A word or phrase that users type into search engines.
  • Organic Traffic: Visitors who come to your site from unpaid search results.
  • SERP (Search Engine Results Page): The page users see after entering a query. It includes organic results, paid ads, and featured snippets.

II. On-Page SEO (Content & HTML)

  • Alt Text: A description of an image in the HTML code, used by screen readers and search engines to understand the image.
  • Content is King: A phrase implying that unique, high-quality, relevant content is the most important success factor.
  • Duplicate Content: Content that appears on the internet in more than one place (URL). Google tries to filter this out.
  • H1 Tag: The main heading of a webpage. It should include the primary keyword.
  • H2-H6 Tags: Subheadings used to structure content hierarchically.
  • Keyword Density: The percentage of times a keyword appears on a page compared to the total word count.
  • Keyword Stuffing: Overloading a webpage with keywords in an unnatural way (negative ranking factor).
  • Long-Tail Keyword: Specific, longer phrases (3+ words) that have lower search volume but higher conversion intent (e.g., "red leather running shoes size 10").
  • Meta Description: A summary of a webpage (150-160 characters) that appears under the title in search results.
  • Title Tag: The clickable headline of a webpage that appears in SERPs and browser tabs.

III. Off-Page SEO (Authority & Links)

  • Anchor Text: The visible, clickable text in a hyperlink.
  • Backlink: A link coming from another website to your own. It is considered a "vote of confidence."
  • Brand Mention: When a website mentions your brand name without hyperlinking to you.
  • DA (Domain Authority): A metric (developed by Moz) predicting how well a website will rank on SERPs (Score 1-100).
  • Dofollow Link: A standard link that passes authority (PageRank) to the destination page.
  • Guest Blogging: Writing content for another company's website to gain a backlink and exposure.
  • Link Building: The active process of acquiring backlinks from other websites.
  • Link Equity (Link Juice): The value or authority passed from one page to another through a hyperlink.
  • Nofollow Link: A link attribute (rel="nofollow") that tells search engines not to pass authority to the destination URL.
  • Toxic Link: A backlink from a low-quality or suspicious website that can harm your SEO.

IV. Technical SEO (Structure & Code)

  • 301 Redirect: A permanent redirect from one URL to another. It passes 90-99% of link equity.
  • 302 Redirect: A temporary redirect. It does not pass link equity.
  • 404 Error: The "File Not Found" status code, meaning the page no longer exists.
  • 500 Error: An "Internal Server Error" where the server fails to fulfill a valid request.
  • Canonical Tag: An HTML tag (rel="canonical") that tells search engines which version of a page is the "master" copy.
  • Core Web Vitals: A set of metrics Google uses to measure user experience: Loading (LCP), Interactivity (INP), and Visual Stability (CLS).
  • Crawl Budget: The number of pages Googlebot will crawl on your site within a given timeframe.
  • HTTPS (SSL): A secure version of the HTTP protocol. It is a lightweight ranking signal.
  • Noindex: A meta tag that explicitly tells search engines not to include a specific page in their search results.
  • Robots.txt: A text file in your site's root directory that instructs crawlers which pages they can or cannot access.
  • Schema Markup: Code (structured data) that helps search engines understand your content better and create "Rich Snippets."
  • Sitemap (XML): A file listing all the important URLs on your site to help crawlers discover them.

V. Metrics & Analytics

  • Bounce Rate: The percentage of visitors who navigate away from the site after viewing only one page.
  • CTR (Click-Through Rate): The percentage of people who see your link in search results and actually click on it.
  • Impression: Each time your URL appears in a search result for a user.
  • KPI (Key Performance Indicator): A measurable value that demonstrates how effectively a company is achieving key business objectives.
  • Organic Reach: The number of people who see your content without paid distribution.
  • Page Speed: The time it takes for a specific page to load.
  • ROI (Return on Investment): The ratio of net profit to cost. In SEO: (Revenue from Organic Traffic - Cost of SEO) / Cost of SEO.
  • Search Volume: The estimated number of times a specific keyword is searched for in a month.

Congratulations! 🎉

You've completed Level 1: SEO Fundamentals! You now understand the language, concepts, and mechanics behind search engine optimization.

Put Your Knowledge Into Practice

With pSEO Wizard, you can apply everything you've learned to generate hundreds of SEO-optimized pages automatically. Start with 10 free pages today!

Ready to Apply What You Learned?

Put your knowledge into practice with pSEO Wizard and generate thousands of SEO-optimized pages.

Start Building Now