As its history indicates, the popular use of the word "racism" is relatively recent. The word came into widespread usage in the Western world in the 1930s, when it was used to describe the social and political ideology of Nazism, which treated "race" as a naturally given political unit. It is commonly agreed that racism existed before the coinage of the word, but there is not a wide agreement on a single definition of what racism is and what it is not. Today, some scholars of racism prefer to use the concept in the plural "racisms", in order to emphasize its many different forms that do not easily fall under a single definition. They also argue that different forms of racism have characterized different historical periods and geographical areas. Garner (2009: p. 11) summarizes different existing definitions of racism and identifies three common elements contained in those definitions of racism. First, a historical, hierarchical power relationship between groups; second, a set of ideas (an ideology) about racial differences; and, third, discriminatory actions (practices).