It is not a secret that people might judge you by the way you speak. For example, if you sound confident, people might trust you.
But for some people, it is also about what accent you have. Studies showed that people might link your accent to not only your place of birth, but also your personal characteristics. Some accents are perceived as "good" or "correct." Listeners think that the speaker is intelligent, honest and hard-working because of their accent. On the other hand, some accents are seen as something negative and needing correction, with speakers seen as less intelligent. Both positive and negative conclusions are stereotypes.
The situation when you are judged by your accent is called “accentism” and is considered a form of discrimination. It is a new concept. It is possible that many people have experienced negative treatment in their daily lives because of their accent but they haven’t noticed it.