Why do some countries have two or more capital cities?

Question

Such as Cape town/Pretoria,South Africa or La Paz/Sucre, Bolivia.

Answer 1

Some countries have different capitals because each city has a different role. Most of the time there are two capitals: one is said to be economic and the other administrative.
In the case of South Africa, there are three capitals, each of them detaining one of the country's power (administrative, legislative and judiciary).