Glossaire · SEO

Semantic silo

A semantic silo is a site architecture method that groups pages covering the same subject into partitioned thematic zones, connected by strict internal linking. Each silo brings together a central page, which covers the topic broadly, and more specific pages that detail its subtopics. Internal links flow primarily within the silo, which concentrates thematic relevance and the semantic signal on a precise scope. For search engines, this organization clarifies the site structure and strengthens its understanding of the topic covered, which improves rankings on related queries. The semantic silo differs from a simple category classification: it relies on the coherence of lexical fields and on a logic of topical authority, where each page contributes to establishing the domain's expertise. This makes the site easier to crawl and easier for engines to map to a clear area of specialization.

A semantic silo organizes a site into coherent thematic zones, each dedicated to a precise topic. This structuring helps both visitors find their way and engines understand the site's scope of expertise.

How it works

A silo consists of a broad central page, often a pillar page, and satellite pages that detail each subtopic. Internal linking connects these pages mainly within the silo, which prevents the signal from being diluted toward unrelated subjects.

In practice, links flow down from the pillar page to the specific pages, back up to it, and laterally between closely related pages. You deliberately limit links leaving the silo to preserve thematic concentration.

Key takeaway

A semantic silo is not just a URL folder: it is above all a logic of lexical coherence and controlled internal links.

A concrete example

An agency covering organic search can create a "technical SEO" silo grouping pages on crawling, indexing, Core Web Vitals, and markup. Each page links to the others in the same silo, and the "technical SEO" pillar page serves as the hub. Another silo, "link building," runs in parallel without mixing with the first.

Why it matters

The semantic silo strengthens topical authority by grouping all relevant content on a subject. For engines, a well-siloed site sends a clear signal of specialization, which improves rankings across the entire set of queries on the theme. In the era of generative engines, this structural clarity also helps models identify and cite pages as reliable sources on a given domain.

FAQ

Questions fréquentes

The semantic silo refers to the overall thematic partitioning of the site's architecture. The semantic cocoon is a more precise linking model, popularized by Laurent Bourrelly, that organizes internal links around a target page according to user needs.

Physical silos rely on the URL architecture, virtual silos only on internal linking. Most sites combine both. The virtual silo offers more flexibility when you cannot restructure existing URLs.

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