If a black person was born in Jamaica, Barbados or Brazil that does not make them African American!!!!! Secondly, responding to the actual question there is no difference between blacks and Jamaicans. Jamaican is just a nationality just like American is, while on the other hand black is a race. Ever heard of the black disapora? Well, many people here (Jamaicans) belong to it since most people here are black, despite the fact that there are other races here too.