SEO techniques can be classified into two broad categories: techniques that search engines recommend as part of good design, and those techniques of which search engines do not approve. The search engines attempt to minimize the effect of the latter, among them spamdexing. Industry commentators have classified these methods, and the practitioners who employ them, as either white hat SEO, or black hat SEO. White hats tend to produce results that last a long time, whereas black hats anticipate that their sites may eventually be banned either temporarily or permanently once the search engines discover what they are doing.
White Hat
An SEO technique is considered white hat if it conforms to the search engines' guidelines and involves no deception. As the search engine guidelines are not written as a series of rules or commandments, this is an important distinction to note. White hat SEO is not just about following guidelines, but is about ensuring that the content a search engine indexes and subsequently ranks is the same content a user will see. White hat advice is generally summed up as creating content for users, not for search engines, and then making that content easily accessible to the spiders, rather than attempting to trick the algorithm from its intended purpose. White hat SEO is in many ways similar to web development that promotes accessibility, although the two are not identical.
Black Hat
Black hat SEO attempts to improve rankings in ways that are disapproved of by the search engines, or involve deception. One black hat technique uses text that is hidden, either as text colored similar to the background, in an invisible div, or positioned off screen. Another method gives a different page depending on whether the page is being requested by a human visitor or a search engine, a technique known as cloaking.
Search engines may penalize sites they discover using black hat methods, either by reducing their rankings or eliminating their listings from their databases altogether. Such penalties can be applied either automatically by the search engines' algorithms, or by a manual site review. One example was the February 2006 Google removal of both BMW Germany and Ricoh Germany for use of deceptive practices. Both companies, however, quickly apologized, fixed the offending pages, and were restored to Google's list.

Search engine optimization (SEO) is the process of improving the visibility of a website or a web page in search engines' "natural," or un-paid ("organic" or "algorithmic"), search results. In general, the earlier (or higher ranked on the search results page), and more frequently a site appears in the search results list, the more visitors it will receive from the search engine's users. SEO may target different kinds of search, including image search, local search, video search, academic search,[1] news search and industry-specific vertical search engines.

White Hat SEO techniques are based on providing customers with relevant and quality content and making it easily accessible over the internet. Their aim is to satisfy the user and not merely search engines, and this is achieved through following all legal guidelines required to implement SEO.

Black Hat search engine optimization is customarily defined as techniques that are used to get higher search rankings in an unethical manner. These black hat SEO techniques usually include one or more of the following characteristics:

-breaks search engine rules and regulations
-creates a poor user experience directly because of the black hat SEO techniques utilized on the Web site
-unethically presents content in a different visual or non-visual way to search engine spiders and search engine users.

Black Hat SEO used to be legitimate SEO techniques; however because of few abusive users they are no longer acceptable by the current SEO communities. Black hat SEO techniques can give a website a short term gains in terms of ranking unlike white hat SEO that can provide a website a long term gains in terms of ranking. You cannot solely rely on utilizing Black hat SEO methods for the risks of being penalized by search engines are higher.

Which kind of SEO techniques are coming under 'white hat' group? We should practice those for better result.

White Hat Seo techniques are those which are prefer by Google and Black hat techniques are those which is not prefer by google.

White hat always give the Good Result than Black hat techniques.

Yes I agreed that, we all should follow white hat link building techniques so as not to get penalized by Google. but black hat SEO also includes some very useful updates and we can not neglect them too.


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SEO Services in Ireland

The white hat SEO technique is legal technique, it follows all rules and regulation of googles. White hat SEO includes following techniques:
Social bookmarking, image backlinking, web 2.0, forum posts etc......
Black hat SEO technique is not good to use.It used to fool google black hat SEO techniques are:
Keyword stuffing, cloaking, doorway pages etc.....