Internal links stay on your domain. They connect your homepage to product pages, blog posts to service pages, or any page to any other page you control. External links point outward to different domains—think Wikipedia citations, supplier references, or industry sources. The functional difference is control and purpose. Internal links let you architect how authority flows through your site. You decide which pages get the most link equity, which conversion paths users follow, and how deep your content hierarchy goes. A strong internal linking structure means Google can crawl efficiently and users can find what they need in two or three clicks. At Ottawa SEO, we typically see sites with 3-5 contextual internal links per page perform better than those with zero or with footer-spam linking schemes. External links serve credibility and context. When you link to Statistics Canada data or a manufacturer's spec sheet, you're telling Google and users that you've done research. It's a trust signal. The outdated fear that external links leak PageRank is mostly myth—Google has explicitly said linking to quality sources doesn't hurt you. What does hurt is linking to spammy directories or irrelevant sites just to reciprocate. Practical distinctions: - Internal links: Use descriptive anchor text that matches target page intent. Avoid generic "click here" unless necessary for UX. You control the destination, so optimize anchor text for both users and crawlers. - External links: Use rel="nofollow" or rel="sponsored" when linking to untrusted or paid sources, but let editorial links remain dofollow. Open in new tab if it improves UX, but that's a design choice, not an SEO rule. Both link types matter. A site with only internal links looks isolated. A site with only external links has no structure. Balance them based on what serves the user's intent on each page, and you'll naturally build both authority and trustworthiness.