What is the difference between de facto segregation and de jure segregation?

De jure segregation is enforced by law...think of bathrooms and water fountains labeled "whites only"

De facto segregation is "enforced" by locals, (both black and white) who feel that the two should not mix. For example, in Orange County and Los Angeles, there is a great deal of this type of segregation. A black man may enter San Clemente or Dana Point any time he wishes, but he may feel very "alone" in the same way a white man wandering around south LA would feel very much an outsider...sadly, if traveling alone, neither is entirely safe from the locals (this includes local law enforcement)

This division has made OC Main, The Men's Central Jail Complex aka CJX a de jure segregated facility...housing or "celling" blacks and whites togther, or even on the same tier or cell block contributes to far too much violence, so the facility is segregated.

de facto segregation exists even though it is not required by law (gradpoint)