SERP (Search Engine Ranking Page) / Ranking
SERP means Search Engine Ranking Page. This is what you look at multiple times a day. It’s the (first) page of results Google gives you when you are searching for a keyword or a keyword combination.
SERP is the position of your website in Google’s search engine results based on a certain keyword combination.
moz.com/search-ranking-factors
Every two years, Moz surveys the opinions of dozens of the world's brightest search marketers and runs correlation studies to better understand the workings of search engine algorithms. Here are the results for 2015.
www.michielgaasterland.com/seo/what-is-the-difference-betwee...
PR is the grade your web page gets from headmaster Google. SERP is the position of the page in Google’s search results based on certain keywords.