It's defined as the racism inherent in the structure of the system, such as longer sentences for crack cocaine (preferred and used mostly by low income black people) versus powder cocaine (preferred and used mostly by well off white people).

Sometimes people use it to describe racism between people, but it's actually supposed to mean the structural racism which exists in a societal system. It doesn't mean that someone designed it that way, but it could have been or it could be an accidental thing.

Discounting a concept because it's used improperly by some of the "other side" is common today but not helpful.