Natural Linking
Describes the hypertext links found on web sites that are part of text content and that link to expanded or additional information on a subject without consideration of their value in link popularity.

Netscape
An early Internet company, since acquired by AOL. The company is famous for its Netscape Navigator browser that dominated the browser scene from 1994 to about 1997.

Nofollow
If you don't want Googlebot to follow a link and index it from your site, you can use the following tag in your href links: rel="nofollow"

Possible uses include channeling of PR away from non-monetary pages such as an "about" page. So, instead of having a live link to the about page, by having the html :

<a href="http://www.example.com/about.html" rel="nofollow">About Us</a>

Googlebot will not:
1.Index the page from that link;
2. Consider the anchor text of the link; or
3. Pass any PR to the linked page.