Link Equity (Link Juice)
Link equity — colloquially called 'link juice' — is the value and [[domain-authority|authority]] passed from one page or domain to another through hyperlinks. When a high-authority site links to a domain, it shares a portion of its ranking power. During [[domain-migration|domain migrations]], [[301-redirect|301 redirects]] transfer approximately 90–99% of link equity from the old URL to the new one, though some fraction is lost at each redirect hop. Link equity also flows internally — a well-structured internal linking architecture ensures authority is distributed efficiently across the entire domain.
Example
A link from Wikipedia to your domain passes significant link equity. Using a 301 redirect when changing domains preserves most of that equity, while a 302 redirect or broken link forfeits it entirely.