Definition of SEO: Search Engine Optimization. That collection of techniques used to ensure the search engines, especially Google, can find and index your site. The techniques break down in several ways:
On-page and off page. Look on this forum for a LOT of information about these.
Black Hat versus White Hat.
- Black hat tecniques are those disapproved of by the search engines, especially Google, since they are designed to deceive the search engine into indexing something where it should not be indexed. Black Hat techniques can get your site banned!
- White hat techniques are non-deceptive techniques.
- Grey Hat techniques are somewhere in the middle. I have been unable to get a good handle on "Grey Hat" techniques, as they seem to vary by intent.
To get a good handle on SEO, go buy a "Complete Idiot's" or "... For Dummies" book on SEO. All the techies I know learn from those books after they have poked around a subject.