What is federal? How to use in English

The word "federal" has its roots in the Latin word "foedus," meaning "covenant" or "treaty." In the 16th century, the term "foederal" was used in English to describe a league or confederation of states or nations. This sense of the word was influenced by the idea of a federal covenant, or a binding agreement between states or nations. In the 18th century, the term "federal" was adopted by American colonists to describe their proposed system of government, in which power would be divided between a central authority and regional governments. This concept was inspired by the Articles of Confederation, which had governed the colonies during the American Revolution. Since then, the term "federal" has come to refer specifically to the government of the United States, with its system of federalism, in which power is divided between the federal government and individual state governments.