Why is the government called the federal government?

Answer 1

The national governments of many countries (US, Canada, Australia, Germany etc...) are called "federal" due to those countries being federations. A federation is a country composed many states that have federated, meaning they have given some portion of their authority (sovereignty) to a central (federal) government in order to better achieve common goals. The term is used to contrast with the governments of the individual states.

Answer

The "Federal Government" refers specifically to the national government, being exclusive of State and Local administrations. State and local governments are often referred to as one thing (think of college classes; one for US Government meaning Federal and another class for State and local government)

The U.S. Constitution establishes a government based on "federalism," or the sharing of power between the national, and state and local governments. Our power-sharing form of government is the opposite of "centralized" governments, such as those in England and France, under which national government maintains total power.

While each of the 50 states has its own constitution, all provisions of state constitutions must comply with the U.S. Constitution. For example, a state constitution cannot deny accused criminals the right to a trial by jury, as assured by the U.S. Constitution's 6th Amendment.