Taxation refers to the act of a taxing authority actually levying tax. Taxation as a term applies to all types of taxes, from income to gift to estate taxes. It is usually referred to as an act; any revenue collected is usually called "taxes."

Taxation can also refer to taxes as an abstract concept, a actual dollar amount of tax that has been levied or the material funds that have been received as taxes. Although all of these definitions are technically correct, the one listed above is the most common. Taxation is one of the primary powers of government over the people.