A topic cluster is a group of related pages with different jobs: a broad pillar introduces the subject, supporting pages answer more specific questions, and internal links help readers move between them. The difficult part isn’t drawing the diagram. It’s deciding which questions deserve their own URLs and which belong together. For an established website,

Parasite SEO is an industry term often used for what Google describes as site reputation abuse: publishing third-party content on a stronger host domain mainly to benefit from that domain’s existing ranking signals. The practice becomes risky when the content has little connection to the host site’s purpose, receives limited editorial oversight, or exists mainly

Subdomains can be useful for separating parts of a website, but they are not a simple SEO shortcut. Google can handle both subdomains and subdirectories, so the better choice depends on users, content ownership, technical setup, and long-term maintenance. This guide explains when a subdomain makes sense, when a subdirectory may be simpler, and which

Duplicate content means the same, or substantially similar, main content is accessible at more than one URL. It is often a URL-management issue rather than a publishing mistake. Google generally chooses a representative, or canonical, URL from a group of duplicates. Having those duplicates does not, by itself, mean a website has been penalised. The

An SEO content strategy is a plan for deciding which pages a site needs, what each page should help a reader do, and when the content should be reviewed. It covers existing pages as well as new articles. A publishing calendar is part of that plan, but a list of deadlines cannot tell you whether

Cornerstone content refers to the pages that explain your website’s most important topics in a clear, useful, and maintainable way. These pages usually act as hubs: they introduce a broad subject, link to supporting articles, and help users understand where to go next. A good cornerstone page is not defined by word count alone. It

SEO-friendly content answers a specific search need clearly, accurately and with enough detail for the reader to make progress. Keywords, headings and internal links help communicate that answer, but they cannot compensate for a page that misses the question. The practical challenge is deciding what belongs in the article and what does not. A writer

Competitor keyword analysis compares the search terms rival websites rank for with the terms your own site appears for. The point is not to reproduce a competitor’s content plan. It is to work out whether a difference in search visibility calls for a better existing page, a genuinely new resource, stronger connections between pages, or

Last reviewed: August 2026. This guide reflects current Google Search documentation and distinguishes the original meaning of Latent Semantic Indexing from the way the phrase “LSI keywords” is commonly used in SEO. “LSI keywords” is an SEO phrase that is still used in content briefs and optimisation tools, but it does not describe a modern

Keyword difficulty (KD) is a third-party estimate of how hard it may be to compete for a search query. It is useful for screening a keyword list, but it is not a Google metric and it is not a verdict on whether your page can rank. A neat score is convenient in a spreadsheet. The

Someone searching for an “SEO audit checklist” probably wants a list they can work through. A search for “SEO audit service” points towards a different task: finding someone to do the work. Both queries concern SEO audits, but an article that treats them as interchangeable may answer neither particularly well. Search intent is the purpose

If you have no budget for a keyword research subscription, start with the question you need answered. Google Autocomplete is a quick way to explore wording. Google Trends shows whether interest is seasonal or changing. Google Search Console is more valuable once your own pages have search impressions. For additional keyword ideas and third-party estimates,

Long-tail and short-tail keywords are best understood as different parts of search demand, not as a word-count contest. Short-tail, or head, keywords usually sit towards the high-demand end of a topic. Long-tail keywords receive fewer searches individually and often express a more specific need. They are frequently longer, but length is only a clue. The

Two searches can use quite different words and still deserve the same page. Two others may look similar but require completely different answers. Keyword research is how you identify those distinctions, investigate demand and competition, and decide which pages your website should create or improve. The result should be more useful than a spreadsheet full

A 404 error appears when a URL cannot be found on the server. In SEO, the goal is not to remove every 404 from the internet. The goal is to identify which missing URLs matter, fix broken internal paths, redirect valuable removed pages to relevant alternatives, and leave genuinely outdated or intentionally removed URLs as

Schema markup and Google rich results are related, but they are not the same thing. Schema.org provides a broad vocabulary for describing a page. Google Search supports only a subset of structured data for specific search features, and that support can change while the underlying Schema.org type remains perfectly valid. That leaves two tests for

Canonical tags are easy to add, but they are also easy to misuse. In many technical SEO audits, the issue is not simply that a page is missing a rel=”canonical” tag. The bigger problem is usually that the canonical tag, internal links, XML sitemap, redirects, and hreflang annotations are all sending different signals. A canonical

A robots.txt file has a narrow job: it tells compliant crawlers which URLs they may request from a particular site origin. That makes it useful for crawl control, but a poor substitute for indexing rules, canonicalisation or access security. The distinction matters because a technically correct Disallow rule can still produce the wrong SEO outcome.

An XML sitemap is a file that lists the important URLs on a website so search engines can discover, crawl, and understand them more efficiently. It does not guarantee indexing, but it gives search engines a clearer roadmap of the pages you want them to consider. For SEO, a sitemap is most useful when it