What is referrer logging and proxy server?
 

I am using opera and in preferences there is an option to enable referrer logging, What does that mean? do I need that and same for proxy server......:confused:

You posted here successfully? Leave proxy setting alone then... Referrer for some page is the page from which you came by link. But it is often spoofed by browser for privacy reasons. Are you really concerned with privacy? If yes, disable. If not and you have troubles with some site redirecting you to front page instead of downloads - enable. Else - leave it alone...