Racism is pretty much undefinable when it comes to certain point, considering the concept of Race is to say we're a completely different breed from one another when we're all really just people. Race is used to describe skin color, and/or culture/ethnicity/continental, basically race is an outdated system since it's true purpose was to classify people by Western stereotypes.... Asian is to say Chinese or Korean, Japanese or something else stereotypical in our minds, but people don't stop to consider that middle east regions, most of Russia, the Indian subcontinent are also in the continent of Asia which would imply those people are also Asian. Black is to say anyone with a brown skin color, note that with Asian those people are identifying with their region, while black and white are meant for people to identify themselves with their skin color.
I could go into more detail on how deeply discrimination is rooted in this system but it's a bit better for people to come to the realizations themselves.
The system of race is meant for people to separate themselves and identify themselves with that race, in contradiction to what most our parents told us which was "be ourselves" we let race take a part in how we define ourselves.