The main difference between the two systems is that in common law countries, case law – in the form of published judicial notices – is of paramount importance, while in civil law systems, codified laws prevail. But these divisions are not as clear as they may seem. In fact, many countries use a mixture of features of the general law and civil law systems. Understanding the differences between these systems first requires understanding their historical underpinnings. A receiving law is a statutory law passed when a former British colony becomes independent, by which the new nation adopts (i.e. receives) customary law before independence, unless it is expressly rejected by the legislative body or constitution of the new nation. Receiving laws generally regard pre-independence English common law and the resulting precedent as standard law, as it is important to use a complete and predictable body of law to regulate the conduct of citizens and businesses in a new state. All U.S. states, with the partial exception of Louisiana, have either introduced admission laws or passed common law through a court notice.  This does not mean that the common law is better in all situations.
For example, civil law may be clearer than case law if the legislator has had the foresight and diligence to deal with the specific facts applicable to a particular situation. For this reason, civil law laws tend to be a bit more detailed than laws written by common law legislators – but conversely, it makes the law harder to read (the U.S. Tax Code is an example).  The example of the evolution of the law of negligence in the preceding paragraphs illustrates two crucial principles: (a) the common law is evolving, this evolution has been in the hands of judges, and judges have been “making laws” for hundreds of years.  (b) The reasons for a decision are often more important in the long run than the outcome in a particular case. For this reason, court opinions are usually quite lengthy and contain justifications and guidelines that can be reconciled with judgment in future cases, rather than the clear rules usually contained in legislation. Edward Coke, Lord Chief Justice of the English Court of Common Pleas of the 17th century and Member of Parliament, wrote several legal texts that brought together and incorporated centuries of jurisprudence. Lawyers in England and America learned the law from its institutes and reports until the end of the 18th century. His works are still cited by common law courts around the world. Today, one-third of the world`s population lives in common law jurisdictions or systems mixed with civil law, including Antigua and Barbuda, Australia, Bahamas, Bangladesh, Barbados, Belize, Botswana, Burma, Cameroon, Canada (both the federal system and all its provinces except Quebec), Cyprus, Dominica, Fiji, Ghana, Grenada, Guyana, Hong Kong, India, Ireland, Israel, Jamaica, Kenya, Liberia, Malaysia, Malta, Marshall Islands, Micronesia, Namibia, Nauru, New Zealand, Nigeria, Pakistan, Palau, Papua New Guinea, Philippines, Sierra Leone, Singapore, South Africa, Sri Lanka, Trinidad and Tobago, United Kingdom (including its overseas territories such as Gibraltar), United States (both the federal system and 49 of its 50 states) and Zimbabwe. Some of these countries have variants of common law systems.
In these countries, the common law is synonymous with jurisdiction. In 1938, the United States Supreme Court in Erie Railroad Co. v. Tompkins 304 USA 64, 78 (1938), set earlier precedents, and stated, “There is no general customary federal law, which has limited federal courts to acting solely as interstitial interpreters of laws that have arisen elsewhere. Z.B. Texas Industries v. Radcliff, 451 U.S. 630 (1981) (Without explicit legal authority, federal courts cannot create rules of intuitive justice, for example, a right to contributions from co-conspirators). After 1938, federal courts that rule on matters that arise under state law were required to refer the interpretation of state laws to state courts or to justify what the highest court of a state would decide if it faced the problem, or to certify the matter to the highest court of the state for resolution. Romano-Dutch common law is a bi-legal or mixed legal system similar to the common law system in Scotland and Louisiana.
Romano-Dutch common law courts include Botswana, Lesotho, Namibia, South Africa, Swaziland, Sri Lanka and Zimbabwe. Many of these jurisdictions recognize customary law and, in some, as . B South Africa, the Constitution requires that the common law be developed in accordance with the Bill of Rights. Romano-Dutch customary law is a further development of Romano-Dutch law by the courts of the Romano-Dutch common law courts. During the Napoleonic Wars, the Kingdom of the Netherlands adopted the French Civil Code in 1809, but the Dutch colonies of the Cape of Good Hope and Sri Lanka, then called Ceylon, were seized by the British to prevent them from being used as bases by the French Navy. The system was developed by the courts and spread with the expansion of the British colonies into southern Africa. Romano-Dutch customary law is based on the legal principles set forth in Roman law sources such as the Institutes and The Digest of Justinian, as well as on the writings of 17th century Dutch jurists such as Grotius and Voet. In practice, the majority of decisions are based on recent precedents.
Public law[a] is the law that governs the relationship between the individual and the state. Private law covers relationships between individuals and other private entities (but may also include “private” relationships between the government and private entities). As early as the 15th century, it became convenient for litigants who felt betrayed by the common law system to call the king personally. For example, they could argue that damages (under the common law (as opposed to equity law)) were not a sufficient remedy for an intruder occupying their lands and instead required that the intruder be evicted. From there developed the justice system, which was administered by the Lord Chancellor in the courts of the Chancellery. It was in the nature of things that equality and justice were often in conflict with each other, and disputes often lasted for years, as one court opposed the other, although in the 17th century. In the nineteenth century, it was established that justice should prevail. The common law was originally a peculiarity of England. Until the Norman Conquest, there were different rules for different parts of the country.
But as the laws and the country began to unite, a common law was created based on customs and decisions throughout the country. These rules evolved organically and were rarely written. .