The role of any national government is to protect the safety and well-being of its citizens and the sovereignty of the country's borders. National government is authorized to act based on a legal constitution, federal laws and accepted civil standards. All citizens benefit from agencies and programs created by national government.
A national government based on Western legal standards has executive, legislative and judicial branches. Each branch operates based on criteria established by constitutional authority. Each branch works individually and collectively to establish and maintain laws for the country as a whole.
The executive branch is headed by an elected, or appointed, leader that oversees and manages the smooth operation of government. The executive branch is also responsible for maintaining diplomatic relations and the military.
The legislative branch is responsible for drafting, writing and passing laws that govern the entire nation. Individual legislatures are elected to represent states or territories within the national governmental framework. Legislation in the form of bills is drafted and debated by the legislative body. A bill becomes law only if a majority vote in favor of passage. Once a law is passed, it applies to the entire country.
The judicial branch is charged with interpreting and executing federal laws as they are written. Laws created by a national government often overrule laws created by more local governments.