Black Hat SEO defined

Black hat seo is:
Unethical SEO. Search Engine Optimization techniques and methods are employes which fall outside of the guidlines issued by the Major Search Engines such as Google, Yahoo and MSN. Implementation of this tyoe of Search Engine Optimization may provide short term gains for your site(s). If you are discovered as using these techniques you can be placed under a penalty by the Search Engine. …

The actual line between the two is quite thin, but, Black Hat SEO refers to things that are considered dark, or spammy, while White Hat SEO refers to “good” SEO. I determine Black Hat SEO as anything that, A. breaks any search engines rules, B. effects the users experience on the site for the worse, or C. shows different content to different user-agents.