Everybody has an accent. A person’s accent can tell us many things about their age, sex, geographical origin, and even educational level or social class. We make assumptions on the basis of these vocal cues and it’s perfectly normal to do so.
An accent, however, shouldn’t tell us anything about a person’s trustworthiness, competence, professional ability or economic status.
These assumptions are prejudices, and if they end up having an impact on the way a person is perceived and treated, they become a form of discrimination.
Accent discrimination is a form of discrimination based exclusively on how a person speaks.