VAT (Value-Added Tax) is a tax added to the price of most goods and services in South Africa. The rate is 15%.
If your business is registered for VAT, you add it to what you sell and collect it from your customers. You can also claim back the VAT you pay on what you buy for the business. You then pay SARS the difference.
It's called "value added" because VAT only falls on the value your business adds along the way.
A registered business is called a VAT vendor. From here, you can check whether you have to register for VAT or weigh up the pros and cons of registering.