In this chapter, foundational concepts in the sociology of race/ethnicity such as race, ethnicity, racism, institutional racism, race privilege, color-blindness, and the social construction of race are introduced. Attention is also given to key demographic shifts that are changing the face of America and, thus, signifying the importance of understanding diversity in order to be successful in the labor force. This chapter also explores the ways race operates at different levels in society, through racial ideologies, institutional racism, and racial identities. In this fourth edition, attention is paid to the ways the COVID-19 pandemic has been raced and to the ways digital technologies reinforce existing racial hierarchies and racism, despite beliefs that they can be free of human biases.