What are the visa & residency requirements in Botswana?

"In order to visit Botswana, foreign nationals must obtain a visa prior to arrival. The process of applying for a visa involves submitting an application form, a valid passport, two passport-sized photographs, and a fee. Depending on the purpose of the visit, additional documents may be required. In order to obtain residency in Botswana, foreign nationals must submit an application form, a valid passport, two passport-sized photographs, a fee, and proof of employment or business activity in the country. Depending on the purpose of the residency, additional documents may be required. The application process may also involve an interview with a representative from the Department of Immigration," mentioned another expat when asked about moving to Botswana.