01 / Fundamentals
This page defines 29 SEO Basics terms. Each entry gives a plain definition, a What to check step you can apply to your own site, and links to deeper SiteAuditLint guides where they exist.
Search engine
A search engine is a system that discovers, stores, and ranks web content so it can return relevant results for a user's query. Google, Bing, and AI-powered answer engines all follow the same broad cycle of crawling, indexing, and ranking.
Know which search engines send meaningful traffic to your site, so you prioritize the right webmaster tools and crawlers.
Go deeper: Introduction to SEO
Crawler
A crawler, also called a bot or spider, is a program that search engines use to fetch web pages and follow their links. Googlebot is Google's main crawler.
Confirm important crawlers are not blocked by robots.txt, firewalls, or bot protection rules.
Go deeper: What is a website crawler and how does it work?
Source: Google Search Central: Overview of Google crawlers
Crawling
Crawling is the process by which search engines discover and fetch URLs, usually by following links and reading XML sitemaps. A page that is never crawled cannot be indexed.
Review the Crawl Stats report in Google Search Console for spikes in errors, slow response times, or sudden drops in crawl requests.
What is the difference between crawling and indexing?
Crawling is fetching the page. Indexing is analyzing it and storing it so it can appear in search results. A page can be crawled and still not be indexed.
Go deeper: Crawling, Crawlability vs indexability
Indexing
Indexing is the process of analyzing a crawled page and storing it in the search engine's index, the database that results are drawn from. Only indexed pages can rank.
Use the URL Inspection tool to confirm key pages are indexed, and review the Page indexing report for pages excluded unexpectedly.
Why is my page crawled but not indexed?
Common causes include thin or duplicate content, a canonical pointing elsewhere, low perceived value, or a noindex directive.
Go deeper: Indexing
Ranking
Ranking is the position a page holds in search results for a given query. Rankings vary by location, device, personalization, and the search features shown.
Track rankings for a defined keyword set over time rather than reacting to single daily checks.
Go deeper: Rankings
Ranking factor
A ranking factor is any signal a search engine uses to decide the order of results, such as relevance, content quality, links, and page experience. Google uses many systems and does not publish weights for individual factors.
Treat claimed ranking factors from third parties as hypotheses and test them against your own data.
SERP
A SERP, or search engine results page, is the page a search engine shows in response to a query. Modern SERPs mix organic results with ads, AI Overviews, featured snippets, local packs, and other features.
Look at the actual SERP for your target query before writing content, so the format matches what already ranks.
Go deeper: What is a SERP? How search engine results pages work
Organic vs paid search
Organic search results are earned through relevance and quality, while paid search results are ads bought through platforms like Google Ads. Paying for ads does not improve organic rankings.
Separate organic and paid traffic in analytics so SEO performance is measured accurately.
On-page SEO
On-page SEO is optimizing elements on the page itself, such as content, title tags, headings, and internal links, to improve relevance and usability.
Audit templates rather than single pages, since one template fix can improve thousands of URLs.
Go deeper: On-Page SEO course
Off-page SEO
Off-page SEO covers actions outside your website that influence rankings, mainly earning backlinks, brand mentions, and reviews.
Monitor new and lost referring domains, and investigate sudden spikes that could signal spam.
Go deeper: Off-page SEO terms
White hat SEO
White hat SEO refers to optimization practices that follow search engine guidelines and focus on users, such as creating helpful content and improving site quality.
Compare tactics against Google Search Essentials before adopting them.
Black hat SEO
Black hat SEO refers to tactics that violate search engine spam policies to manipulate rankings, such as cloaking, keyword stuffing, and buying links. These tactics risk manual actions and algorithmic demotions.
Audit inherited sites for hidden text, doorway pages, and paid link patterns.
Local SEO
Local SEO is optimizing a business's online presence to appear in location-based searches, such as "dentist near me" and Google Maps results.
Make sure your business name, address, and phone number match across your site, Google Business Profile, and directories.
Go deeper: Local SEO checklist
Google Business Profile
Google Business Profile is Google's free listing tool for local businesses, controlling how a business appears in Maps and the local pack.
Verify categories, hours, and service areas are accurate, and respond to reviews consistently.
NAP consistency
NAP consistency means a business's Name, Address, and Phone number appear identically across the web. Inconsistent details can weaken local search trust.
Search for old addresses or phone numbers and correct outdated directory listings.
Local pack
The local pack is the map and set of business listings Google shows for queries with local intent.
Track local pack visibility separately from organic rankings, ideally from multiple locations.
Featured snippet
A featured snippet is a highlighted answer shown near the top of the SERP, extracted from a web page. It usually appears as a paragraph, list, or table.
Answer the target question directly in the first sentence under a matching heading.
How do I get a featured snippet?
You cannot opt in. The best approach is a concise, accurate answer to the exact question, placed immediately below a relevant heading.
People Also Ask
People Also Ask, or PAA, is a SERP feature showing expandable related questions, each with a short answer pulled from a web page.
Collect PAA questions for your target queries and answer the relevant ones clearly within your content.
Knowledge panel
A knowledge panel is an information box Google shows for entities such as people, organizations, and places, drawn largely from the Knowledge Graph.
Keep your organization's details consistent across your site, structured data, and authoritative profiles.
Rich results
Rich results are enhanced search listings that show extra information, such as review stars, product prices, or event dates, usually enabled by structured data.
Validate markup with Google's Rich Results Test and monitor enhancement reports in Search Console.
Go deeper: Missing schema issue
Zero-click search
A zero-click search is a search where the user gets their answer on the SERP and does not click any result. AI Overviews and featured snippets increase zero-click behavior.
Measure impressions and visibility alongside clicks, since rising zero-click behavior can lower CTR without a loss in rankings.
Algorithm update
An algorithm update is a change to how a search engine ranks results. Google makes thousands of changes a year, most of them unannounced.
Annotate known update dates in your reporting so traffic changes are not misattributed to site changes.
Go deeper: How the September 2026 update affects rankings
Core update
A core update is a significant, broad change to Google's ranking systems, announced several times a year. Core updates reassess overall content quality and relevance rather than targeting specific issues.
Compare affected pages against the ones that gained, and wait until the rollout completes before drawing conclusions.
How do I recover from a core update?
There is no specific fix. Google advises improving overall content quality and helpfulness, and recovery often shows only after a later update.
Spam policies
Spam policies are Google's published rules describing manipulative practices that can lead to lower rankings or removal from results, such as scaled content abuse and link spam.
Review programmatic and AI-assisted content workflows against the scaled content abuse policy.
Go deeper: Google September 2026 spam update
Manual action
A manual action is a penalty applied by a human reviewer at Google when a site violates spam policies. It can affect specific pages or the whole site.
Check the Manual actions report in Search Console after any unexplained, sharp traffic drop.
PageRank
PageRank is Google's original algorithm for measuring a page's importance based on the quantity and quality of links pointing to it. It is still part of Google's systems, though public PageRank scores were retired years ago.
Use internal linking to direct link value toward your most important pages.
Semantic search
Semantic search is a search engine's ability to understand the meaning and context of a query, not just match its exact words.
Cover a topic's related concepts and entities naturally instead of repeating one exact-match keyword.
Go deeper: Keyword vs entity optimization
Knowledge Graph
The Knowledge Graph is Google's database of entities and the relationships between them, used to power knowledge panels and understand queries.
Use Organization or Person structured data with sameAs links to help Google connect your entity correctly.
Passage ranking
Passage ranking is Google's ability to rank a specific section of a long page for a query, even when the page as a whole covers a broader topic.
Give each section a clear heading and a self-contained answer so individual passages can be understood on their own.
Sources
Official documentation referenced on this page:
Browse the full SEO terms glossary, or run a technical SEO audit with SiteAuditLint to check these signals on your own site.