Oxford definition of racism:
the belief that all members of each race possess characteristics, abilities, or qualities specific to that race, especially so as to distinguish it as inferior or superior to another race or races: theories of racism
prejudice, discrimination, or antagonism directed against someone of a different race based on the belief that one’s own race is superior:
Pointing out a difference doesn't make that person racist. Believing that you're better than them on the basis of that difference makes you racist. But since we've become so overly sensitized to the possibility that we might be viewed as racist, we tend to shy away from anything that might remotely resemble a racist remark, it's really hard to have an intelligent conversation about it. Russell Peters does it better than most by using humour...