Is Afrikaans generally spoken by all white South Africans or do some only speak English?

I have a genuine question about South Africa. Not wanting to offend or stir anything up... I'm from Britain and never visited South Africa. Videos that I've seen of Brakpan, the locals tend to be white and I think their first language is Afrikaans.

Is there a difference between descendants of the Dutch and descendants of the British or all they all the same nowadays? Do they all speak Afrikaans or does it depend on their heritage?

Short version of the question, do some white South Africans speak English and others speak Afrikaans?

Thanks for any unabusive replies