Holocaust denial is the belief that the Holocaust did not occur as it is described by mainstream historiography.
Key elements of this belief are the explicit or implicit rejection that, in the Holocaust:
The Nazi government had a policy of deliberately targeting the Jews and the Gypsies for extermination as a people;
Between five and six million Jews were systematically killed by the Nazis and their allies.
Tools of efficient mass extermination, such as gas chambers, were used in extermination camps to kill Jews.
In addition, most Holocaust denial implies, or openly states, that the current mainstream understanding of the Holocaust is the result of a deliberate Jewish conspiracy created to advance the interest of Jews at the expense of other nations.
Most historians and scholars reject Holocaust denial as "grounded in hatred, rather than any accepted standards of assertion, evidence, and truth" and a "pseudoscience" that "rejects the entire foundation of historical evidence," instead motivated by an anti-Semitic ideology.
Some of the most prominent representatives of Holocaust deniers have been shown in court to have a pattern of falsifying historical documents (e.g. David Irving) or deliberately misrepresenting historical data (e.g. Ernst Zündel). This history of Holocaust deniers distorting, ignoring, or misusing historical records has led to almost universal condemnation of the techniques and conclusions of Holocaust denial, with organizations such as the American Historical Association, the largest society of historians in the United States, stating that Holocaust denial is "at best, a form of academic fraud."
Similarly, Public Opinion Quarterly, summarizing the work on the subject done by a range of historians including Jaroff, Lipstadt, Riech, Ryback, Shapiro, Vidal-Naquet, Weimann, and Winn concludes "No reputable historian questions the reality of the Holocaust, and those promoting Holocaust denial are overwhelmingly anti-Semites and/or neo-Nazis."
Many Holocaust deniers insist that they do not deny the Holocaust, preferring to be called "Holocaust revisionists". They are nevertheless commonly labeled as "Holocaust deniers" to differentiate them from historical revisionists and because their goal is to deny the existence of the Holocaust, as it is commonly understood, rather than honestly using historical evidence and methodology to examine the event.