Key Difference: White Hat SEO tactics and strategies are those optimization strategies, techniques and tactics that are considered acceptable and ethical by the search engines, especially by Google. Black Hat SEO tactics and strategies, on the other hand, are those strategies that are considered unethical by search engines, i.e. especially by Google.

SEO stands for Search Engine Optimization. Basically, it refers to a series of tactics and strategies that are used to increase the visibility of the website in search engines such as Google, Bing, Yahoo, etc., as well as to increase the number of visitors to the website. However, there are a variety of ways thorough which this can be achieved; some are very popular, whereas others are looked down upon. These strategies are categorized into three primary categories, White Hat SEO, Black Hat SEO, and Grey Hat SEO tactics. Each one is different.  

White Hat SEO tactics and strategies are those optimization strategies, techniques and tactics that are considered acceptable and ethical by the search engines, especially by Google. These types of strategies focus on actual human audience, rather than just machine generated numbers. These strategies completely follows search engine rules and policies, hence the name, white hat, similar to the context white collar.

White Hat SEO tends to focus on relevancy and organic ranking. It tends to utilizes strategies such as using keywords and keyword analysis, backlinking, link building to improve link popularity, and writing content for human readers. White Hat SEO is also referred to as Ethical SEO.

Black Hat SEO tactics and strategies, on the other hand, are those strategies that are considered unethical by search engines, i.e. especially by Google. These types of strategies do not focus on actual human audience but instead are just focused on improving their numbers, regardless of whether or not those numbers actually correspond to an audience.