Before the difference between Black Hat and White Hat SEO can be explained, the term SEO must be understood. SEO stands for Search Engine Optimization. Search Engine Optimization is the practice of attempting to raise the standing or ranking of a website in the search results of various search engines. When someone searches for information, a list of websites will appear. These are websites that the search engine believes have information relevant to that for which the user is searching. It is generally accepted that as websites appear closer to the first listing presented, more visits to the website will result. If the website is one for a business or one that relies on advertising within the website for income, this can be very important.
Since it is important to website owners that their websites are well-placed in search results, website designers try to build and maintain websites to match the criteria that search engines use to give high rankings. There are now consultants and entire companies devoted just to researching search engine methods and providing website owners with SEO services, advising website them how to change and update their content to get their websites ranked higher in search results. These consultants are also called Search Engine Optimizers; thus, the term SEO can refer to the practice of Search Engine Optimization or an expert in this field.
The term White Hat SEO refers to practitioners who attempt to gain their results by studying search engine methods, staying up-to-date on changes and improvements in search engine technology and using methods accepted by the industry. They advise their clients on the best ways to arrange and write their content to make it most likely to be found by search engines and to be highly rated.
Black Hat SEO uses methods that are generally seen as being unacceptable to search engine owners and to others in the industry. Although labeling some of these methods as Black Hat is somewhat arbitrary, some methods are almost universally seen as being unacceptable. Methods such as spam, repeating terms that are unrelated to the website's content, hidden words and redirecting to other websites are generally considered to be Black Hat.
Labeling various methods of SEO as White or Black Hat is often arbitrary. In general, Black Hat relies on methods that try to trick or deceive the search engine into giving a higher rating or directing users to the website. White Hat tries to use an understanding of the search engine's programming to increase the quality of the website and make it more usable while also increasing its ranking. In either case the ultimate goal is to increase traffic to a website by encouraging search engines to rank the website higher in its listings.
I am a professional .NET and PHP software developer. I has been designing and developing websites professionally since 1994. Currently working as SEO consultant at UK SEO Company.