PageRank named for Larry Page, one of the guys who developed the algorithm, is the probability theory that analysis the probability of a user, landing on a particular page, when someone searches for specific information.
In a way, PageRank is a Search Engine's vote of confidence, that a website has the best information, relevant to the search words keyed in by the user.
How Do Search Engines Assign PageRanks?
Consider a webpage A with information about Columbus. There are several other webpages as well with information on Columbus. But most of them have links leading back to webpage A, citing it as the source of information or telling you that webpage A has informative posts on similar topics. Obviously webpage A is well liked by people researching Columbus. Therefore, the Search Engines too like webpage A and assign it a good PageRank. Webpage A, now that it's loved by both the browsers and the Search Engines get s assigned either Page 1 or Page 2 in the Search Engine Results Page (SERP).
- PageRank of the blog.
- Whether the articles in the blog are relevant.
- If the blogger is authoritative enough in her chosen field in order to have several other websites post a link to hers.