SEO has its own vocabulary, and it can be overwhelming when you are just starting out. This glossary covers every term you are likely to encounter, explained simply so you can understand what your SEO agency or marketing tools are telling you.
- Alt Text
- A text description added to an image in your HTML. It tells search engines and screen readers what the image shows. Every image on your site should have descriptive alt text.
- Anchor Text
- The clickable text in a hyperlink. Using descriptive anchor text (like "SEO services" instead of "click here") helps Google understand what the linked page is about.
- Backlink
- A link from another website to yours. Backlinks are one of the strongest ranking signals — each quality backlink is like a vote of confidence in your content.
- Black Hat SEO
- SEO techniques that violate Google's guidelines, such as buying links, keyword stuffing, or cloaking. These can result in your site being penalised or removed from search results entirely.
- Bounce Rate
- The percentage of visitors who leave your site after viewing only one page. A high bounce rate may indicate that your content does not match what the visitor was looking for.
- Canonical Tag
- An HTML tag that tells Google which version of a page is the "official" one. Used to prevent duplicate content issues when the same content is accessible at multiple URLs.
- Click-Through Rate (CTR)
- The percentage of people who see your listing in search results and click on it. A higher CTR signals to Google that your result is relevant and useful.
- Content Marketing
- Creating and sharing valuable content (blog posts, guides, videos) to attract and engage your target audience. Good content marketing naturally supports SEO by earning links and traffic.
- Core Web Vitals
- A set of three metrics Google uses to measure user experience: Largest Contentful Paint (loading speed), Interaction to Next Paint (responsiveness), and Cumulative Layout Shift (visual stability). These are confirmed ranking signals.
- Crawling
- The process by which Google's bots (called Googlebot) discover and read web pages. If Google cannot crawl your page, it cannot rank it.
- Domain Authority (DA)
- A score from 0 to 100 developed by Moz that predicts how likely a domain is to rank in search results. It is based on the quantity and quality of backlinks. Not a Google metric, but a useful proxy.
- Domain Rating (DR)
- Ahrefs' equivalent of Domain Authority. Measures the strength of a website's backlink profile on a scale of 0 to 100.
- Duplicate Content
- Content that appears on more than one URL. Google tries to pick one version to rank and may ignore the others. Use canonical tags to tell Google which version you prefer.
- E-E-A-T
- Experience, Expertise, Authoritativeness, Trustworthiness — the criteria Google uses to assess content quality. Particularly important for health, finance, and legal content (YMYL topics).
- Featured Snippet
- A highlighted answer box that appears at the top of some Google search results, above position 1. Often pulled from a page that ranks in the top 10. Structuring content with clear headings and concise answers increases your chances of winning one.
- Google Business Profile
- Google's free business listing that appears in Maps and local search results. Essential for any business serving a specific area. Formerly called Google My Business.
- Google Search Console
- A free tool from Google that shows how your site performs in search results — which keywords you rank for, your average position, clicks, and any technical issues Google has found.
- H1 Tag
- The main heading on a page. Each page should have exactly one H1 that contains the primary keyword and accurately describes the page content.
- Hreflang
- An HTML attribute that tells Google which language and regional variant a page is intended for. Used on multilingual sites to ensure the right version appears for each audience.
- Impressions
- The number of times your page appeared in Google search results, regardless of whether anyone clicked on it. Visible in Google Search Console.
- Indexing
- The process of Google adding a page to its database so it can appear in search results. A page that is not indexed will never rank. Check indexing status in Google Search Console.
- Internal Link
- A link from one page on your website to another page on the same website. Internal links help Google discover your content and understand your site structure.
- Keyword
- A word or phrase that people type into Google. Your goal is to have your pages appear when people search for keywords relevant to your business.
- Keyword Cannibalisation
- When multiple pages on your site compete for the same keyword. This confuses Google about which page to rank and often results in neither performing well.
- Keyword Density
- The percentage of times a keyword appears in your content relative to the total word count. There is no ideal density — write naturally. If it reads awkwardly, you have used the keyword too many times.
- Keyword Difficulty (KD)
- A score estimating how hard it is to rank on page 1 for a specific keyword. Based primarily on the backlink profiles of currently ranking pages. Check any keyword with our Keyword Difficulty checker.
- Keyword Stuffing
- Unnaturally cramming keywords into your content, meta tags, or alt text. This is a black hat technique that can result in penalties. Google is very good at detecting it.
- LCP (Largest Contentful Paint)
- A Core Web Vital measuring how long it takes for the largest visible element (usually an image or heading) to load. Google recommends under 2.5 seconds.
- Link Building
- The process of acquiring backlinks from other websites to yours. Ethical link building focuses on creating valuable content that naturally attracts links, guest posting, and digital PR.
- Local Pack
- The map and three business listings that appear at the top of Google results for local searches (e.g., "plumber near me"). Powered by Google Business Profile data.
- Local SEO
- Optimising your online presence to attract customers from local searches. Involves Google Business Profile, local keywords, directory listings, and reviews.
- Long-Tail Keyword
- A longer, more specific keyword phrase (e.g., "best plumber in Truro for boiler repairs" vs. "plumber"). Lower search volume but much less competition and higher conversion rates.
- Meta Description
- A brief summary of a page's content that appears below the title in search results. Should be under 155 characters and written to encourage clicks. Not a direct ranking factor but affects CTR.
- Mobile-First Indexing
- Google primarily uses the mobile version of your site for indexing and ranking. If your site looks different or has less content on mobile, that is what Google sees.
- NAP
- Name, Address, Phone number. These must be identical across your website, Google Business Profile, and all directory listings for local SEO to work properly.
- Nofollow
- A link attribute that tells Google not to pass ranking authority through the link. Used for paid links, user-generated content, and untrusted sources.
- Organic Traffic
- Visitors who arrive at your website by clicking on unpaid (non-ad) search results. The primary goal of SEO is to increase organic traffic.
- Page Speed
- How quickly your web page loads. Affects both rankings and user experience. Test with Google PageSpeed Insights or our Site Audit tool.
- PageRank
- Google's original algorithm for measuring page importance based on backlinks. While the public PageRank score was retired in 2016, the underlying concept still influences rankings.
- People Also Ask
- A Google SERP feature showing related questions with expandable answers. Appearing here can significantly increase your visibility. Structuring content around common questions helps.
- Redirect (301/302)
- A 301 redirect permanently sends visitors and search engines from one URL to another, passing most ranking authority. A 302 is temporary and does not pass authority. Always use 301s when permanently moving pages.
- Referring Domain
- A website that links to yours. Having 50 backlinks from one referring domain is worth less than 50 backlinks from 50 different referring domains.
- Robots.txt
- A text file that tells search engine crawlers which pages or sections of your site they should not access. Located at yoursite.com/robots.txt.
- Schema Markup
- Structured data added to your HTML that helps Google understand the content type (e.g., product, recipe, FAQ, business). Can result in rich results like star ratings, FAQs, and price information in search results.
- Search Intent
- The reason behind a search query. There are four main types: informational (learn something), navigational (find a specific site), commercial (research before buying), and transactional (ready to buy).
- SERP
- Search Engine Results Page — the page Google shows after you type in a search query. Includes organic results, ads, featured snippets, and other features. Preview how your pages appear with our SERP Preview tool.
- Site Audit
- A comprehensive review of a website's technical SEO health, identifying issues that could prevent it from ranking well. Run a free check with our Site Audit tool.
- Sitemap (XML)
- A file listing all the important pages on your website, submitted to Google via Search Console. Helps Google discover and index your content more efficiently.
- SSL Certificate
- A security certificate that enables HTTPS on your website. Without it, browsers show a "Not Secure" warning and Google may rank you lower.
- Technical SEO
- The process of optimising the technical aspects of a website (speed, crawlability, indexing, mobile-friendliness, structured data) to help search engines access and understand your content.
- Title Tag
- The HTML element that defines the title of a web page. Appears as the clickable headline in search results. Keep under 60 characters and include your target keyword.
- Traffic
- The number of visitors to your website. Can be organic (from search), direct (typing your URL), referral (from other sites), social (from social media), or paid (from ads).
- URL
- Uniform Resource Locator — the web address of a page (e.g., googlerankingchecker.com/seo-glossary). Short, descriptive URLs with hyphens perform better than long, parameter-heavy ones.
- User Experience (UX)
- How easy and pleasant your website is to use. Google measures aspects of UX through Core Web Vitals and uses them as ranking signals. Good UX also reduces bounce rates and increases conversions.
- White Hat SEO
- SEO techniques that follow Google's guidelines and focus on providing value to users. Sustainable and risk-free, unlike black hat methods that may provide short-term gains but risk penalties.