What on Wikipedia may refer to the following:

• What Wikipedia is not; list of things Wikipedia is, and things that Wikipedia isn't;
• What is an article?; Wikipedia articles – what are they?;
• What adminship is not; an essay summing up points of what Wikipedia's requests for adminship process isn't;
• What "Ignore all rules" means; more detailed information about what Wikipedia's policy "ignore all rules" means;
• What the GFDL is not; list of things the GFDL license is, and things that the GFDL license isn't;
• What Google liked; a now inactive page listing some of the most highly viewed pages that link from the search engine giant Google;
• "What is a ..." may also refer to many different criteria guidelines:
  • What is a good article?
  • Featured article criteria
  • Featured list criteria
  • Featured topic criteria
  • Featured picture criteria
  • Featured sound criteria
• What Wikipedia Wants; a rejected proposal, outlining content that Wikipedia wants in articles;
• What You Need To Know About Cancer booklets; public-domain text available for use on Cancer-related articles;
• What administrators do; outlining details of what the job of an administrator entails;
• What is a troll?; help resource for "troll"-related issues;
• What is a wiki for; what exactly is a "wiki", and why is the Wikipedia a "wiki"
• What Would Britannica Do; how would the editors of Encyclopedia Britannica and other encyclopedias do in the situation, or how would they write a certain piece of content;
• What claims of relevance are false; an essay with guidelines on determining whether a certain "claim of relevance" is false, or otherwise;
• What would Jack do?; similar to the Britannica essay above, instead asking the question "What would Jack do?" (Jack, in this case, is a trusted and respected editor); or
• Why was my page deleted?; guidelines for answering the question "Why was my page deleted?".