Quora - A place to share knowledge and better understand the world.

REFERENCE
Quora is a research/polling reference website with a question and answer format. Questions are asked, answered, and edited by the community of users also responsible for organizing the questions into appropriate, easy-to-find categories. 

Users can work together by editing questions as well as suggesting edits that other users have already submitted. A bit like a combination of Facebook and Twitter, Quora has the largest usage base in the United States, about 37%. Quora has its own proprietary algorithm to rank answers similar to Google PageRank. Quora also uses Amazon Elastic Compute Cloud technology to host the servers that manage the site. 

The website was launched in 2010.