Link juice is a colloquial SEO term describing the value of backlinks to a webpage. The number and quantity of these links determine the composition of the link juice. Link juice is seen as an important factor for ranking highly in Google.
When many people think of link equity, they also think of PageRank. PageRank was Google's first algorithmic calculation used to determine how a site should rank, based primarily on that site's backlink profile.
PageRank is no longer the main determinant for a site's ranking; it's now only one of the hundreds of ranking factors Google looks at, and its importance is much diluted these days.
Link juice is a term in SEO (Search Engine Optimization) that references the amount of authority or value that one backlink passes to the website it connects with. In the SEO industry, link juice is also called “link equity”.
Backlinks from websites with higher authority and relevance on a topic will generate more link juice and help a page rank better in the search engines.