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 hidden text, 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. Another category sometimes used is grey hat SEO. This is in between black hat and white hat approaches, where the methods employed avoid the site being penalized but do not act in producing the best content for users. Grey hat SEO is entirely focused on improving search engine rankings.
It might be awkward, but please don't scroll past this. This Monday we humbly ask you to defend Wikipedia's independence. Our 2019 fundraiser will be over very soon. 98% of our readers don't give; they look the other way. If you are an exceptional reader who already donated, we sincerely thank you. If all our readers donated just $2.75 today, Wikipedia could keep thriving for years. Most people donate for a simple reason—because Wikipedia is useful. If Wikipedia gave you $2.75 worth of knowledge this year, take a minute to secure its future with a gift to the Wikimedia Endowment. Show the volunteers who bring you reliable, neutral information that their work matters. Thank you.