Racism is the belief in the superiority of one race over another, which often results in discrimination and prejudice towards people based on their race or ethnicity. As of the 2000s, the use of the term "racism" does not easily fall under a single definition.
Today, most biologists, anthropologists, and sociologists reject a taxonomy of races in favor of more specific and/or empirically verifiable criteria, such as geography, ethnicity or a history of endogamy. To date, there is little evidence in human genome research which indicates that race can be defined in such a way as to be useful in determining a genetic classification of humans.
Sociologists, in general, recognize "race" as a social construct. This means that, although the concepts of race and racism are based on observable biological characteristics, any conclusions drawn about race on the basis of those observations are heavily influenced by cultural ideologies. Racism, as an ideology, exists in a society at both the individual and institutional level.