A more thorough explanation:

Roman–Dutch law is a legal system that was used in Holland from the mid-15th century to the early 19th century. It was based on a combination of Germanic customary law and Roman law, as interpreted in medieval and Renaissance law books. The system of law was named by Simon van Leeuwen, who used it as the sub-title of his work entitled Paratitla Juris Novissimi, published at Leyden in 1652.

The principles of Roman-Dutch law were carried by the Dutch into their settlements in the East and West Indies. When some of these territories, such as the Cape of Good Hope, Ceylon, and part of Guiana, became British colonies, the old law was retained as the common law of these territories. With the expansion of the British Empire in South Africa, the Roman–Dutch Law became the common law of the whole area comprised within the Union of South Africa.

Today, Roman-Dutch law forms the basis of modern South African law, the law of several other countries in southern Africa, and the law of Sri Lanka.

One example of Roman-Dutch law is the principle of "good faith" in contract law. This principle requires that parties to a contract act honestly and fairly towards each other. If one party breaches this principle, the other party may be entitled to cancel the contract or claim damages.

Another example is the principle of "delict" in tort law. This principle holds that a person who causes harm to another person must compensate them for the harm caused. For example, if a driver causes an accident that injures another person, the driver may be held liable for the harm caused and may be required to pay compensation to the injured person.

These examples illustrate how Roman-Dutch law has influenced modern legal systems in various countries. The principles of Roman-Dutch law have been adapted and developed over time, but they continue to play an important role in shaping the law in these countries.