Google's way of estimating how important a web page is

There's a surprisingly simple answer: PageRank is Google's way of estimating how important a web page is.

Google's system for ranking web pages

PageRank is Google's system for ranking web pages.

a link analysis algorithm, , named after Larry Page and used by the Google Internet search enginethat assigns a numerical weighting to each element of a hyperlinked set of documents, such as the World Wide Web, with the purpose of 'measuring' the purpose's relative importance within the set

Wikipedia says 'PageRank is a link analysis algorithm, named after Larry Page and used by the Google Internet search engine, that assigns a numerical weighting to each element of a hyperlinked set of documents, such as the World Wide Web, with the purpose of 'measuring' the purpose's relative importance within the set. '

a link analysis algorithm used by the Google Internet search engine that assigns a numerical weighting to each element of a hyperlinked set of documents

PageRank is a link analysis algorithm used by the Google Internet search engine that assigns a numerical weighting to each element of a hyperlinked set of documents.

just one element of Google’s ranking algorithm

PageRank is just one element of Google’s ranking algorithm, so PageRank ’s just one of the elements I consider.