Types of SEO Explained: The Complete 2026 Breakdown

Almost everything in SEO sits under three core types. They map directly onto how search engines work — crawl, index, rank (explained in What is SEO?). Get these three right and the specialised types become extensions of them rather than separate skills.

• Technical SEO — can search engines access, render and index your site? This is the foundation.
• On-page SEO — is each page relevant and well-structured for what people search?
• Off-page SEO — does the wider web trust your site enough to rank it?

On-page SEO is everything you optimise on your own pages to make them relevant, clear and easy to understand — for both people and search engines. It’s the most controllable type because it’s entirely in your hands.

Key tasks: keyword and intent mapping, title tags and meta descriptions, heading structure (H1–H3), high-quality content that matches intent, internal linking, image optimisation (alt text), clean URLs, and on-page schema. For how it compares to off-page in detail, see on-page vs off-page SEO.

Off-page SEO builds your site’s reputation and authority from outside it. The biggest signal is backlinks — links from other sites that act as votes of confidence — but it’s broader than that.

Key tasks: earning quality, relevant backlinks; digital PR and outreach; broken-link building; brand mentions; and reviews. The golden rule: quality and relevance beat quantity — a few strong, relevant links outweigh hundreds of weak ones, and manipulative link buying risks penalties.