An authority site is a very high quality website building that is respected by knowledgeable people in its industry. It is a website that has content on it that is so good and makes the Web deign site so useful that people are actually glad they landed on it and want to share it with their friends.
PR is short form of Page Ranking. It is a grading system devised and adopted by google to rank the sites on the internet using a formula of their own.
Numbers are given from 0-10 with zero being the base and 10 is the maximum upper grade!
PR0 Indexed
PR1 Lowest Popular
PR2 Lower Popular
PR3 Low Popular
PR4 Popular
PR5 High Popular
PR6 Higher Popular
PR7 Highest Popular
PR8 Very Popular
PR9 Very Much Popular
PR10 Search Engines
Only according to my personal 5 years experience…