Federal Income Tax

What Does Federal Income Tax Mean?
A tax levied by the United States Internal Revenue Service (IRS) on the annual earnings of individuals, corporations, trusts and other legal entities. Federal income taxes are applied on all forms of earnings that make up a taxpayer's taxable income, such as employment earnings or capital gains.

Investopedia explains Federal Income Tax
It is important to distinguish between the general notion of income tax and federal income tax. In the United States, governments at the state level may also levy income taxes in addition to federal income taxes. Not all states have implemented state level income taxes. For example, the states of Texas and Florida are just two of the handful of states in which federal income taxes are the only income taxes that are levied.