### Instruction:
What is apartheid, and which country experienced it?

### Input:
Portugal's overseas presence in sub-Saharan Africa (most notably in Angola, Cape Verde, Mozambique, Guinea-Bissau, and São Tomé and Príncipe) lasted from the 16th century to 1975, after the Estado Novo regime was overthrown in a military coup in Lisbon. Rhodesia unilaterally declared independence from the United Kingdom in 1965, under the white minority government of Ian Smith, but was not internationally recognized as an independent state (as Zimbabwe) until 1980, when black nationalists gained power after a bitter guerrilla war. Although South Africa was one of the first African countries to gain independence, the state remained under the control of the country's white minority through a system of racial segregation known as apartheid until 1994.

### Response:
Apartheid is a system of racial segregation in South Africa.