1. The Legal Systems of The World
Legal system refers to a procedure or process for interpreting and enforcing the law. It elaborates the rights and responsibilities in a variety of ways.
The contemporary legal systems of the world are generally based on one of three systems: civil law, common law, statutory law, religious law or combinations of these.
Common law system (Case law).
Civil law system (Code law)
Religious law system (e.x: Sharia law)
or combinations of these.

2. Common law system
Common law: (also known as judicial precedent or judge-made law, or case law)  is that body of law derived from judicial decisions of courts and similar tribunals. The defining characteristic of “common law” is that it arises as precedent. 
Countries following a common law system are typically those that were former British colonies or protectorates, including the United States.

3. Features of a common law system include:
There is not always a written constitution or codified laws;
Judicial decisions are binding – decisions of the highest court can generally only be overturned by that same court or through legislation;
Extensive freedom of contract - few provisions are implied into the contract by law;
Generally, everything is permitted that is not expressly prohibited by law.

4. Civil law system
Civil law, civilian law, or Roman law is a codified system of law. It takes its origins from Roman law.
Countries following a civil law system are typically those that were former French, Dutch, German, Spanish or Portuguese colonies or protectorates, including much of Central and South America. Most of the Central and Eastern European and East Asian countries also follow a civil law structure.

5. Features of a civil law system include:
There is generally a written constitution based on specific codes (e.g., civil code, administrative law, tax law and constitutional law) enshrining basic rights and duties;
Only legislative enactments are considered binding for all. There is little scope for judge-made law in civil, criminal and commercial courts
In some civil law systems, e.g., Germany, writings of legal scholars have significant influence on the courts;
Courts specific to the underlying codes – there are therefore usually separate constitutional court, administrative court and civil court systems that opine on consistency of legislation and administrative acts with and interpret that specific code;
Less freedom of contract - many provisions are implied into a contract by law and parties cannot contract out of certain provisions.

6. Religious law system
Religious law refers to the notion of a religions system or document being used as a legal source though the methodology used varies.
The main kinds of religious law are Sharia in Islam, Halakha in Judaism, and canon law in some Christian groups.
Religious law countries: Sudan, Saudi Arabia, Iran Bangladesh, the Gambia.

7. Pluralistic law system
There are some countries that using two types of the legal systems. These countries are called pluralistic countries.
Example for Civil law and common law countries: Israel , malta
Civil law and religious law countries Afganistan, Indonesiam ,Bahreyn.
Common law and religieus law countries: Malaysia, negeria.