PageRank
PageRank
PageRank is the foundational algorithm that Larry Page and Sergey Brin built Google on. The core idea is elegant: a link from one page to another is a vote of confidence, and votes from pages that themselves have many votes count more. It treats the web as a giant graph and calculates the probability that a random person clicking links would end up on any given page. While the public PageRank toolbar score was retired years ago, the underlying principle of link-based authority still drives how Google evaluates pages.
In practice, PageRank shaped the entire SEO industry. It is why link building became a discipline, why guest posting became a strategy, and why link spam became a problem Google has spent two decades fighting. Understanding PageRank helps you grasp why not all links are equal — a single link from a highly authoritative, relevant site can move the needle more than hundreds of links from low-quality directories. It also explains why internal linking matters: you are distributing your own site’s authority through the links you control.
For anyone working in growth or digital marketing today, PageRank is less about the specific formula and more about the mental model. Authority flows through links. Your job is to earn links from places that matter and structure your site so that authority reaches the pages you want to rank. That principle has not changed in 25 years, even as Google has layered hundreds of other signals on top of it.