Search Engine Optimization is the process of improving the visibility of a website on organic ("natural" or un-paid) search engine result pages (SERPs), by incorporating search engine friendly elements into a website. A successful search engine optimization campaign will have, as part of the improvements, carefully select, relevant, keywords which the on-page optimization will be designed to make prominent for search engine algorithms. Search engine optimization is broken down into two basic areas: on-page, and off-page optimization. On-page optimization refers to website elements which comprise a web page, such as HTML code, textual content, and images. Off-page optimization refers, predominantly, to backlinks (links pointing to the site which is being optimized, from other relevant websites).

Types of SEO

As the colors of the types of search engine optimization suggest, there are stark differences in the approach and long-term results of white hat and black hat search engine optimization. Though both types of SEO have their proponents, most companies/websites with long-term, stable, and sustainable goals will tend to stay away from the dark-colored variety.

Here is a quick overview:

	White Hat SEO	Black Hat SEO
Definition	White hat SEO utilizes techniques and methods to improve the search engine rankings of a website which don't run afoul of search engine (mainly Google) guidelines.	Black Hat SEO exploits weaknesses in the search engine algorithms to obtain high rankings for a website. Such techniques and methods are in direct conflict with search engine guidelines.
Wholesomeness Level	High	Very Low (not wholesome at all if you ask those in charge of cleaning search engine result page spam)
Techniques	Some white hat SEO techniques include: high quality content development, website HTML optimization and restructuring, link acquisition campaigns supported by high quality content and manual research and outreach.	Some black hat SEO techniques include: link spam, keyword stuffing, cloaking, hidden text, and hidden links.
What to Expect	Steady, gradual, but lasting growth in rankings.	Quick, unpredictable, and short-lasting growth in rankings.

The work of most search engine optimization companies, however, operate in a gray area, aptly named Gray Hat search engine optimization. Whether by design or pressure from clients to deliver results, many search engine optimization companies try to deliver solutions and results for customers by utilizing techniques which don't quite cross the line into black hat SEO, but are well outside of what would be considered white hat search engine optimization.

Gray hat search engine optimization is recognizable by 'affordable' pricing, since the search engine optimization company has to reduce cost by resorting to questionable techniques in order to deliver results, instead of highly involved campaign activities.

In the end there is really no 'right' or 'wrong' way to do search engine optimization, but those shopping for SEO services should be aware of the different types and approaches so that they know the level of risk