Internal linking is the practice of using HTML anchor elements to link from one page on your domain to another page on the same domain. The basic syntax is <a href="/target-page">anchor text</a>, where the href attribute points to a relative or absolute URL on your site and the anchor text is the clickable text users see. These links serve three functions. First, they distribute PageRank (link equity) across your site, strengthening pages that might not earn external backlinks. Second, they create pathways for users to discover related content, which improves engagement metrics and time on site. Third, they signal topical relationships to search engines, helping Google understand which pages are authoritative on specific topics. The HTML attributes matter. Rel="nofollow" blocks PageRank flow, which is rarely needed for internal links. The title attribute adds a tooltip but carries minimal SEO weight. Anchor text should be descriptive ("Ottawa keyword research services" beats "click here") because Google uses it to understand the target page's topic. Common mistakes include orphan pages with zero internal links, over-optimization (stuffing exact-match keywords into every anchor), and linking only from navigation menus instead of contextual in-content links. The most powerful internal links come from relevant body content, not sidebars or footers, because they carry contextual weight. At Ottawa SEO, we typically place 2–5 contextual internal links per 1,000 words, prioritizing pages we want to rank and using varied, natural anchor text. We audit for orphans quarterly and build topic clusters where pillar pages link to supporting articles that link back. A 500-page site might have 2,000–4,000 internal links if structured properly. The goal is a shallow click depth (most pages reachable in 3 clicks from the homepage) and a logical hierarchy that mirrors your keyword strategy, not just random cross-linking for the sake of it.