SALSA and PageRank are algorithms that analyze the link structure of web pages to determine authoritative pages. SALSA models the web as two Markov chains, with pages as either hubs or authorities. It computes hub and authority scores to find the principal community of related pages. PageRank also models the web as a graph, and defines a page's rank based on the ranks of pages that link to it, effectively modeling a random web surfer. Both leverage the concept of a random walk on the link graph to determine important pages.