What is the difference between black hat SEO and white hat SEO?

Black hat seo techniques help to rank your keywords faster in search engines and generates more traffic in shorter time. But the methods followed are not supported by Google and hence your website can get penalized for following such techniques.

White hat techniques are those that follow Google webmaster guidelines and hence keeps your webpages safe in Google SERPs.

The difference between black hat SEO and white hat SEO has to do with the techniques used when trying to improve a website's search engine ranking. ... White hat SEO refers to the use of techniques and strategies that target a human audience opposed to a search engine.

Black Hat Strategies
•   Duplicate Content
•   Invisible Content and Stuffed Keywords
•   Cloaking or re-directing the user to another site or page
•   Link from sites with non-relevant content
White Hat Strategies
•   Relevant Content
•   Well labeled images
•   Relevant links and references
•   Complete sentence with good spelling and grammar
•   Unique and relevant page title

Black hat SEO means attempting to move up the rankings by doing things that violate Google's terms of service.

White hat SEO means attempting to move up the rankings while staying within Google's terms of service.