SEO Glossary: 50 Terms Every Business Owner Should Know

The Essential SEO Glossary

Algorithm: The set of rules Google uses to rank web pages. Google's algorithm updates hundreds of times per year. Major updates (like Panda, Penguin, Helpful Content) can significantly shift rankings. Alt text: A written description of an image, added in HTML. Helps search engines understand what images show. Also improves accessibility for visually impaired users. Anchor text: The visible, clickable text in a hyperlink. "Click here" is poor anchor text. "SEO audit tool for small businesses" is good anchor text. Backlink: A link from another website pointing to yours. One of the most important ranking factors. Quality matters more than quantity. Bounce rate: The percentage of visitors who leave your site after viewing just one page. High bounce rates on key pages can indicate poor relevance or user experience. Canonical tag: HTML code that tells search engines which version of a page is the "official" one, preventing duplicate content issues. Click-through rate (CTR): The percentage of people who click your result after seeing it in search results. CTR = clicks / impressions. Content gap: Keywords that competitors rank for that you don't. Identifying and filling content gaps is a common SEO strategy. Conversion: A desired action on your website — a purchase, contact form submission, phone call, or sign-up. Core Web Vitals: Google's metrics for user experience: LCP (load speed), INP (interactivity), CLS (layout stability). Crawling: The process by which search engines discover web pages by following links. Domain authority (DA): A metric (created by Moz, not Google) that predicts how well a website will rank. Higher DA generally correlates with better rankings, but it's not a Google signal. Duplicate content: Content that appears in substantially similar form at multiple URLs. Featured snippet: A selected search result that appears above organic results in a special box — sometimes called "position zero". Google Business Profile: Google's free business listing that appears in Google Maps and local search results. H1/H2/H3: HTML heading tags. H1 is the main page heading. H2 and H3 are subheadings. Used to structure content for both readers and search engines. Hreflang: An HTML attribute that tells Google which language and region a page is intended for. Important for multilingual sites. Impression: Each time your page appears in search results, regardless of whether it's clicked. Index / Indexing: Adding a page to Google's searchable database. If a page isn't indexed, it can't rank. Keyword: A word or phrase that people type into search engines. Targeting the right keywords is central to SEO. Keyword cannibalization: When multiple pages on your site target the same keyword, competing against each other. Keyword density: How frequently a keyword appears on a page. Not a useful metric for modern SEO — focus on natural language. Keyword difficulty: A score (usually 0–100) estimating how hard it is to rank for a keyword. Lower scores = easier to rank. Landing page: The first page a visitor sees when arriving from a specific source (like organic search). Link building: The process of acquiring backlinks from other websites. Link equity: The SEO value that passes from one page to another through links. Also called "link juice" or PageRank. Long-tail keyword: A longer, more specific search phrase. Lower search volume but higher intent and less competition. Meta description: The short description that appears under your page title in Google results. Not a direct ranking factor, but affects click-through rates. Meta title / Title tag: The page title that appears in Google results and browser tabs. One of the most important on-page ranking factors. Mobile-first indexing: Google's approach of primarily using the mobile version of a site for ranking decisions. NAP: Name, Address, Phone number. Consistency of NAP across the web is an important local SEO signal. Noindex: An instruction to search engines not to include a page in their index. Organic traffic: Visitors who arrive from non-paid search results. PageRank: Google's original algorithm for measuring the importance of web pages based on the quantity and quality of links pointing to them. Redirect: Forwarding one URL to another. A 301 is permanent; a 302 is temporary. Rich results: Enhanced search listings with visual elements — star ratings, images, FAQs — enabled by structured data. Robots.txt: A file that tells search engine crawlers which pages they can and can't access. Schema markup: Code added to web pages to help search engines understand the content. Can enable rich results. Search intent: The underlying goal behind a search query — informational, navigational, commercial, or transactional. Search volume: How many times a keyword is searched per month. Used to prioritise keyword targeting. SERP: Search Engine Results Page — the page Google shows in response to a search. Sitemap: A file listing the pages on your website, submitted to search engines to aid discovery and indexing. Structured data: Standardised code (usually JSON-LD) that explicitly describes the content of your pages to search engines. Technical SEO: Optimisation of the technical aspects of a website — speed, crawlability, indexing, HTTPS, structured data. Title tag: See meta title. URL slug: The part of a URL after the domain name. yoursite.com/seo-guide — "seo-guide" is the slug. User experience (UX): How easy and pleasant a website is to use. Increasingly important as a ranking signal via Core Web Vitals. XML sitemap: See sitemap. YMYL: Your Money Your Life. Pages that affect a person's health, finances, safety, or happiness. Google holds these to a higher standard of expertise and trustworthiness. Zero-click search: A search that's answered directly on the SERP, without the user clicking through to a website. Featured snippets, knowledge panels, and local packs are common zero-click results.