Assuming this is a discussion on desegregation busing in the US:
When schools became desegregated in law, black and white communities were still extremely geographically segregated from institutionalized racism (blacks faced enormous discrimination in job opportunities and housing). Schools were still overwhelmingly segregated based on other forms and effects of segregationist policy.
Blacks also did not have the same legacy of inherited wealth that whites had, and schools have mostly been funded at a local level in the US. Thus, white schools had decent funding - often with wealth generated by the expropriated labor of slaves from the grandchildren or great grandchildren of slaveowners - and the black schools were lacking in resources.
Busing was a program of de facto integrating the schools, wherein portions of black communities were given access to higher quality education at a school in a (generally and relatively speaking) more affluent white community.
I m sure that there are people who would want to imagine that there is some "racist" reason to integrate schools in this way, but anyone who believes things like that has absolutely no sense of history. The truth is that black people in the US were never compensated in any meaningful way for the labor that was stolen from them by slavery and the torture and abuse they endured, just given small concessions.