What is PageRank?
PageRank is an algorithm invented by one of Google's founders: Larry Page.
This algorithm is probably the most famous algorithm related to SEO all over the world. Yet it is just one of the many other algorithms used by Google.
PageRank is based on the analysis of links.
Considering that a link pointing from a site A to a site B is a kind of recommandation, Google wanted to count all these links in order to establish a sort of global graph and eventually make their results more relevant.
Beyond the quantitative aspect, a qualitative approach has long been added. In that respect, not all links are equal and some recommendations are better rated than others.
The impact of some links can even be totally absent if Google decides to not give them any credibility.
Through the years , SEO professionals consideration for PageRank has decreased a lot. Actually, its value is no longer exported. However, even if it is no longer shared, it remains at the base of the Google search engine and probably keeps a significant importance in the ranking of web pages.
As for Google, it would very frequently calculate this indicator without releasing it.
Anyway, if you have the opportunity to get a link from a page with a strong PageRank , it would be a shame not to take it.