Hello. The word's etymology can help to undestand the concept. It comes from the verb "to prejudge" (now, the verb "to prejudice" also exists), which is composed of the prefix pre- (before) and the verb "to judge". So, it literally means "judging someone or something before you know him/her/it". Prejudice is, then, "an unfair feeling or opinion formed without thinking deeply or without enough knowledge". A good example is "racial prejudice".

“Prejudice” is a preconceived preference or idea, a judgment or opinion formed beforehand or without knowledge or examination of the facts. It is usually used in a negative sense, an adverse judgment or opinion, and I think most Americans would consider the word to mean a dislike of certain cultural groups, although it can also indicate a bias in favor of something, as in “I’m prejudiced in favor of this plan.” BTW, the words “to discriminate” and “discrimination,” which are commonly used in the same sense as “prejudice”, would also be interpreted by most Americans to have a negative connotation, although the principle meaning is simple “to make a clear distinction.” To be a discriminating person was once something people aspired to. However, because of decades of association with attitudes of one cultural group toward another, those two a words are used almost entirely with a negative connotation in the US.

Sorry, couldn't resist posting this. :) PREJUDICE: http://www.youtube.com/watch?v=KVN_0qvuhhw

Prejudice is attitude that you don't like somebody or something. What's more, discrimination is behavior that you show your disliking