Actually there are three types of SEO Hats:

White Hat SEO
White Hat SEO is also known as organic search engine optimization or natural search engine optimization. White hat SEO is the legitimate use of keyword-focused copy and tags, Search Engine Submissions and a quality Backlinks network to improve sites position, Page Rank, CTR(Click through rate). If site is having a good reputation in search engine postions then it is better to use white Hat SEO techniques instead of black hat techniques. White hat SEO does not include Cloaking, Spam or any other Black Hat SEO techniques. The results which come from white hat techniques are long term.

* No Risk

* User Friendly

* Follow Guidelines

* Long Term Results(It takes Long time to get approved)

Black Hat SEO
In Black hat SEO optimization is mainly done in an unethical manner. This incudes cloaking, spam, violating search engine rules. If a search engine finds a site with black hat SEO techniques then it will remove that site from search engine index. Black Hat SEO techniques can give immediate results but it is very risky. The results will not stay longer and also it effects the site position in SERPs.

* High Risk

* Not User Friendly

* voilating search engine guidelines

* All Scraped Content


Gray Hat SEO
Actually Gray Hat SEO falls in between Black Hat SEO and White Hat SEO. In some cases Gray hat SEO techniques can be legitimate or illegitimate. Such techniques include Gateway Pages, Cloaking ,Doorway Pages, and duplicate content.

* Some what Risk Reward

* Some What User Friendly

* Keeps in Mind (SEO Guidelines)

* Semi Unique

* Less Effort Than WHITE HAT.