What term is used to describe a preconceived opinion about people from different ethnic backgrounds?

The term "prejudice" is specifically used to describe an unfounded or preconceived opinion about individuals based on their ethnic background or other characteristics. Prejudice often involves negative attitudes and beliefs that are not based on personal experience or knowledge but are instead rooted in stereotypes and cultural biases. This can lead to unfair treatment of individuals or groups simply because they belong to a certain ethnicity or culture.

In contrast, discrimination involves action taken against a group or individual based on these prejudicial beliefs, while segregation refers to the physical or social separation of groups from each other. Stereotyping involves generalizing characteristics to all members of a certain group, which can certainly inform prejudicial beliefs but does not capture the full concept of having a preconceived opinion. Therefore, "prejudice" is the most accurate term to denote an opinion that arises prior to actual interaction or understanding of individuals from diverse ethnic backgrounds.