College students need to write various papers when they go to school. How to evaluate the value of a paper? This is a famous saying. When writing a thesis, most of us can't completely innovate new content. We need to "stand on the shoulders of giants" and help explain our views by quoting other people's articles or opinions. When you quote other people's opinions, in a sense, you think their articles or opinions are valuable. One person said it was valuable, and two people said it was valuable. As more and more people say it is valuable, his paper becomes more and more important.

From the background of this PR, we can roughly guess the approximate algorithm of PR value. If you compare a paper to a page and quote other people's articles to represent links, then the general idea of PR value production will appear:

There are three pages: A, B and C. When B page is created, it is linked to A page, and when C page is created, the PR value of A page is the highest.