Apartheid was bad because people of color couldn't marry whites. Blacks had less rights than whites; they got paid less, and were housed in fenced, patrolled barracks.
Living with apartheid was awful; there was so much segregation among races, unfair treatment, and murders constantly. Comparing this to something happening now, Nelson Mandela was similar to Martin Luther King Jr. They're similar because he also had a speech about fighting for equal rights, he was prepared to die for his beliefs.