The instalment sale agreement is the default in South Africa, and it is what most people mean when they say vehicle finance. The credit provider settles the purchase price with the seller, the car is registered in your name with the lender noted as titleholder, and you repay a fixed amount every month until the balance is cleared. Ownership passes to you with the final instalment and the lender releases the papers.
What used to be sold as hire purchase now sits under the same heading. The National Credit Act treats both as instalment agreements, so the disclosure rules, the affordability assessment and the fee caps are identical. The practical differences live in the small print, not the label on the form.
Because no residual amount is waiting at the end, the instalment is the highest of the mainstream options and the total cost of credit is the lowest. If you intend to keep the car for years after it is paid off, this is almost always the structure that leaves you with the most money.