Income tax refers to annual taxes levied by the federal government and most state governments on individual and business income. By law, businesses and individuals must file federal and state income tax returns every year to determine whether they owe taxes. Governments use the taxes they collect to fund their activities.
How it works
Income tax is applied to both earned income (wages, salaries and commission) and unearned income (dividends, interest and rents).
The U.S. and many other countries employ a progressive income tax system in which higher income earners pay a higher tax rate compared to their lower earning counterparts. The intent of progressive systems is to distribute wealth more evenly across a population.