Glossary
Technical SEO
Technical SEO is the work of making sure search engines can reach, read and index your pages at all.
It covers speed, crawlability, duplicate pages, broken links, redirects and how the site is structured underneath. None of it is visible to a visitor, and all of it decides whether your content is ever considered.
Why it matters to you
Content on a site search engines struggle with is content nobody reads. This is unglamorous and it comes before anything else, because writing more pages does not help if the existing ones cannot be crawled.
An example
A site that returns a different page at both the www and non-www address is competing with itself. One redirect fixes it, and the pages that were splitting their signals start ranking as one.
Where this comes up: search engine optimisation .