Canonical Tag: A canonical tag, also known as a "rel=canonical" tag, is an HTML attribute used by search engines to determine the preferred version of a web page when multiple pages have similar or duplicate content. This tag helps search engines to properly index and rank the desired version of the page, avoiding duplicate content issues and improving SEO performance. By implementing canonical tags, website owners can consolidate link equity, directing search crawlers to the most relevant and authoritative version of a page.