A term similar to separation is segregation. A distinction is sometimes made between segregation as being involuntary (such as due to laws) and/or partial and separation as being a voluntary and/or a more complete process, which may imply territorial separation of the different groups into different, homogeneous territories.
Certain historical systems, such as the racial segregation in the United States and the apartheid system in South Africa, included limited racial separateness for the races co-existing in the same territory, but modern supporters usually see these as insufficient and advocate completely separate territories. White supremacism, as implying Whites ruling over and co-existing with non-Whites in the same area, is not supported.
White separatism does not necessarily hold Whites to be superior to other races. It is possible to advocate for racial separation by arguing that racial separatism would be beneficial for all groups, due to factors such as problems caused ethnic heterogeneity and mixed race groups having problems due to genetic outbreeding depression and psychological issues caused by identity issues.
Reasons such as argued differences regarding average genetics may also be cited. Genetics may argued to be the root cause and a fundamental necessity for the modern Western civilization created by Europeans. Insufficient separatism and changes due to causes such as mass migration and race mixing may be argued to be the downfall of many previous civilizations.
The many forms of White flight can be seen as related to a desire for White separatism.