"Otherness"

In his work, 'Orientalism', Edward Said argues that the West, through hegemony, has come to define the non-West, what he calls 'the Orient', in a way which emphasises stereotypical differences so that the indigenous people of colonised nations are not presented as normative, but as different, often exotic, strange, or savage. 

This process of "Othering" legitimises Western supremacy and limits the people of colonized nations as being able to define themselves, for they are defined by the West, and "Othered".

In short, "Othering" emphasises the differences of a group so that they do not fit a normative experience and, therefore, exclusion or ideologies where they are inferior can be justified.