The system of rules that a country or community recognizes as regulating the actions of its members. Law can be created by a legislature through statutes; by the executive through decrees and regulations; or, in common law jurisdictions, by judges through decisions that become binding precedent.
Legal systems are complex because they must balance several purposes: promoting social justice, maintaining the status quo, and keeping the peace. Some governments do better than others at meeting these goals. For example, an authoritarian government might keep the peace, but it may also oppress minorities or political opponents. The framers of the United States Constitution set out to ensure that one person could not control all the power in our nation by separating the legislative, executive, and judicial branches of government.
A lawyer is a professional who studies and argues the rules of law. There are two types of lawyers in the United States: transactional lawyers who write contracts and litigators who go to court on behalf of their clients. In the United Kingdom, these professionals are known as solicitors and barristers.
The concept of law varies with time and place. Culture plays a large role in establishing the principles behind many laws. For example, a culture might value ideas like privacy or fair treatment of all people regardless of race or wealth. Religion can also play a role in law. For example, the Jewish Halakha and Islamic Sharia rely on religious teachings to inform their laws. The Christian Canon law is also informed by religious doctrine.