The Wikipedia definition seems to indicate it has origins as a racist term and I’ve never understood why unix users have adopted this terms instead of something benign like “themes” or “theming” which I remember being in use long before I ever heard “rice”. So what gives? Why use “rice” instead of “theme”?
Japanese and korean aren’t races, they’re nationalities.
They are also different ethnic groups, but that’s still not the same thing as race.
Race is an arbitrary grouping by skin color and/or other purely superficial physical traits. Ergo, racism is based on that as well.
Someone that’s the same race, but a different ethnic group would be prejudice or bigotry, not racism. When it’s divided by geographic boundaries too, that would be a form of nationalism.
Bigotry, racism, and prejudice are sometimes used synonyms, but they aren’t, really. They’re very closely related on that they all address forms of discrimination coupled with “hate”. Hate is in quotes be because you can be prejudiced and just be an idiot rather than hating a given group. Pretty much impossible to be a bigot or a racist and not harbor hate to some degree.