From Wikipedia.org: Law (from the late Old English lagu of probable North Germanic origin) in politics and jurisprudence, is a set of rules or norms of conduct which mandate, proscribe or permit specified relationships among people and organizations, intended to provide methods for ensuring the impartial treatment of such people, and provide punishments of/for those who do not follow the established rules of conduct.
Law is typically administered through a system of courts, in which judges hear disputes between parties and apply a set of rules in order to provide an outcome that is just and fair. The manner in which law is administered is known as a legal system, which typically has developed through tradition in each country.
Legal practitioners, most often, must be professionally trained in the law before they are permitted to advocate for a party in a court of law, draft legal documents, or give legal advice.
The Practice of Law is typically overseen by either a government organization or independent regulating body such as a bar association or barrister society. To practice law--i.e., appear in front of a judge on behalf of someone, draft legal documents, etc.--the practitioner must be certified by the regulating body. This usually entails a two or three-year program at a university’s faculty of law or a law school, which earns the student either an LLB or a JD degree. This course of study is followed by an entrance examination (e.g., bar admission). Advanced law degrees are also often pursued, though they are academic degrees and are not required for the practice of law. These include a Masters of Law (LLM), a Master of Legal Studies (MLS), and a Doctor of the Science of Law (JSD).
Once accredited, a legal practitioner will often work in a law firm, as well as in government, a private corporation or even work as a sole practitioner. Another option is to become a legal researcher, which provides on demand legal research like CommandLaw.com.
A significant component to the practice of law in the common law tradition involves legal research in order to determine the current state of the law. This usually entails exploring case reporters, legal periodicals, and legislation. The same is true in civilian systems when the interpretation of the law is not clear.