Well if you really wnat to know …. nofollow is an HTML attribute value used to instruct some search engines that a hyperlink should not influence the link target’s ranking in the search engine’s index. It is intended to reduce the effectiveness of certain types of search engine spam, thereby improving the quality of search engine results and preventing spamdexing from occurring.

PageRank was developed at Stanford University by Larry Page (hence the name Page-Rank) and later Sergey Brin as part of a research project about a new kind of search engine. The project started in 1995 and led to a functional prototype, named Google, in 1998. Shortly after, Page and Brin founded Google Inc., the company behind the Google search engine. While just one of many factors which determine the ranking of Google search results, PageRank continues to provide the basis for all of Google’s web search tools.

PageRank is based on citation analysis that was developed in the 1950s by Eugene Garfield at the University of Pennsylvania, and Google’s founders cite Garfield’s work in their original paper. By following links from one page to another, virtual communities of webpages are found. Web link analysis was first developed by Jon Kleinberg and his team while working on the CLEVER project at IBM’s Almaden Research Center.