Here’s a great little tool for learning various SEO terms, the SEO Glossary wiki.  http://www.seoglossary.com/

Whenever you come across an SEO term you’re not sure about, check it out in this site.  And while you’re there, learn a few more terms!

This site is a wiki (which means anyone, including you, can edit each definition).  For more about wiki’s, click here: http://en.wikipedia.org/wiki/Wiki