The standard answer is three types of clusters, but how you define them matters for execution. Topic clusters are the pillar-subpage model everyone talks about: one comprehensive pillar page linking to 8-15 supporting articles on subtopics. This is what HubSpot popularized and what most agencies mean when they say "cluster." Semantic clusters group content by search intent and keyword relationships rather than strict hierarchy. You might have five articles targeting different angles of "Ottawa home renovation costs" that cross-link based on user journey, not a rigid pillar structure. Internal linking clusters focus on site architecture: grouping pages by how they pass authority and guide crawlers, which matters more on larger sites where you need to control PageRank flow. At Ottawa SEO, we build topic clusters for new content campaigns but audit existing sites for semantic and linking opportunities first, because most businesses already have scattered content that just needs better organization. The distinction between cluster types gets blurry in practice. A well-executed topic cluster naturally creates semantic relationships and smart internal linking. The mistake is treating clusters as a content template rather than a strategic framework. We see clients publish a pillar page and ten articles, interlink them once, then wonder why rankings don't move. The cluster needs ongoing expansion, updating the pillar as subtopics evolve, and building secondary connections between subtopics. For local businesses in competitive markets like Toronto or Vancouver, even a modest 1 pillar plus 6-8 subtopics can outperform scattered blog posts if the internal linking is tight and the content actually answers clustered search intent. The type of cluster matters less than whether it reflects how your audience actually searches and moves through information.