Link Metrics, PageRank & Domain Authority
Link Metrics is the name referring to the criteria for ranking search results. They reflect the significance of any given webpage on the internet, and include some measure of domain authority, relevancy and trust. It’s a method to measure sites not by how important their webmasters say they are, but by how authoritative, relevant and trusted other web users say they are.
Search engines determine a page’s ranking based on an assessment of its inbound links. Each link from another site is considered as a vote or endorsement from that site for your site. The more endorsements, the more authoritative, relevant and trusted your website must be, and thus the higher its search engine page ranking, or SERP.
PageRank is an example of a link metric algorithm which acts as a key marker of content quality. PageRank is a score from 1-10 for a page based on how many inbound links it has, and how strong those links are. It’s logarithmic, meaning it’s 10x harder to get from 2 to 3 as it is to get from 1 to 2.
When a site links to your swebsite, or when you link internally from one of your pages to another, the link passes ranking points. This is called “link juice”. It generally follows that the higher the PageRank or Trust Rank etc. of a particular page, the more ‘link juice’ that page can pass to other pages through its links.