Racism is a system in which a dominant race believe they are superior and benefit from the oppression of other races - whether they want to or not.

We don't live in a society where every racial group has equal power, status and opportunity.

Yes, white people all over the world throughout history have experienced slavery and persecution but have not been enslaved, colonised or forced to segregate on the scale that black people have. They do not face housing or job discrimination, police brutality, poverty or incarceration at the levels that black people do. This is not to say that they do not experience things like poverty and police brutality at all but again, not on the same scale - not even close.

Racism also crosses religious and cultural boundaries. Islamophobia is racism mixed with cultural intolerance. Islamophobia targets markers of moslem identity. Evident in how perpetrators of Islamophobic hate crime disproportionately target visibly moslem women, in the same way that racism often targets people for the colour of their skin. Islamophobes often target Sikhs because Sikhs wear turbans, wrongly believing only moslems wear turbans.

Racism isn't one race hating another, that's something you tell kids, i.e. when kids ask where do babies come from, you explain it at a level they understand, you don't get too technical.

Unfortunately many people never look into racism and their understanding of racism never advances beyond the kindergarten definition.