There are different categories of law in every country and a lawyer has to be well-versed in all these categories. Following are the main categories of law existing in most countries -
Civil Law
This category deals with lawsuits and other hearings where there is no accusation of a crime. Both sides are private parties and nobody is usually remanded to judicial custody over the issue at hand, but the court can issue rulings which make people carry out certain obligations, refrain from acting in a certain manner and/or award monetary compensations.
Criminal Law
This category covers the cases which deal with crimes. In these cases, either the government or a certain private party brings a litigation of crime against the accused party. The government prosecutes the accused in court on the strength of conclusive evidence of guilt beyond a reasonable doubt. In certain exceptions such as rape, in some countries such as India, the responsibility is on the accused to prove he is not guilty, failing to prove this he is sentenced to a punishment. In certain other theocracies such as in some Islamic-law ruled countries, a woman who brings a case of being a rape victim is regarded as guilty and punished unless she proves herself to be innocent as a non-accomplice in the act, supported by witnesses. These are exceptional cases; otherwise the legal system follows the concept of innocent till proven guilty.
Administrative Law
This type of law deals with the internal running of government departments and services. It varies from department to department according to the nature and need of the department.
Corporate Law
Both civil and criminal laws deal with regulating corporations and their proper conduct in the society. This includes aspects such as accounting regulations and financial fraud (Criminal) as well as consumer rights and service quality (Civil).
Constitutional law
This area deals with an overall handling of the interpretations of Constitutional statutes. This is used in cases such as the political matters and also in public interest litigations (PILs).
Defence Law
Defence services in most countries such as India may have their own judicial system. Accused defence personnel are tried and punished by the defence courts according to their own set of rules, which follow the guidelines of the Constitution. This is called Court Martial. Prisoners of Wars are also tried by Court Martial and defence courts have to follow the UN Convention of trying the prisoners of war on the same lines as their own soldiers. The lawyers and the judges in the Court Martial are from the Defence Service itself; hence a non-defence lawyer is not involved in this. However, a person willing to join the defence and providing his services for the Court Martial should be conversant with the Defence laws which are taught in the defence legal academies.
Civil and Criminal laws have further sub-categories. For example, family laws dealing with divorce, alimony and maintenance are a sub-category of civil laws. Similarly, traffic laws are a sub-category of criminal laws.