Redirection is the process whereby a user is sent to a web page other than that he wanted to access in the first place. The most common redirection method is the “301 Redirect”.
The referrer is the web page URL on which a user found an URL which directed to your page.
The relevancy of a page how a search engine will attempt to measure the pertinence of a web page with regard to the query of the user.
This lets you specify if a particular page should not be indexed by a search engine.
RSS (Really Simple Syndication) is a list of a website’s with new or updated content. It was developed to allow different news services for syndication of content by displaying links, articles summaries and headlines on other web sites.