Domain age is age of your domain. Domain age factor is often misinterpreted i.e domain alone cannot speak for the quality of a website. You can get complete information about a domain from the “whois” data, a place where you register and submit your complete information namely registrants, administrative information and expiration dates..
Domain age is not a major factor in determining your ranking. Google stresses on quality of the content and the links pointing back to a domain so it is wiser to spend more time developing a quality site as compared to looking through lists of domain names to try and find which one is the best..
Refer to this link for more information on domain age.
http://www.searchenginejournal.com/d...-for-seo/7296/
Refer to this link by Matt cutts
http://www.youtube.com/watch?v=-pnpg00FWJY