This chapter examines the discourses of race and ethnicity, and the particularities of defining difference on both sides of the Anglo-American Atlantic. Hence the reference to the 1997 advertising campaign for Guinness beer, 'not everything in black and white makes sense', seemed apt given the array of terminologies which have been used to describe non-whiteness, and the difficulties that each has had in articulating it throughout history into the 21st century. The chapter seeks to explain the choice of ethnicity as the focus of the research by discussing the historical and cultural specificity of definitions of difference. It distinguishes between terms which define difference essentially, such as 'race' and 'nation', and those which encompass diverse experiences and subjectivities. The chapter delineates between the concepts of race and ethnicity. It argues that there exists a struggle over the meaning of ethnicity, but proposes that it is in its definition that makes ethnicity appropriate for the purposes of this research.