PageRank is a method for ranking web pages based on the link structure of the web. It was developed by Google to help search engines make sense of the vast heterogeneity of the World Web. PageRank works by treating individual pages as nodes and links between pages as edges, then recursively propagating importance weights through this link structure. It helps address issues like some pages having many low-quality backlinks versus others having a few highly important backlinks. PageRank models the probability of a person randomly clicking on links by treating it as a random walk through the link graph.