Throughout the year, a variety of things that affect your income taxes can happen. In the United States, a personal income tax return is a set of forms provided by the Internal Revenue Service (IRS) which most residents are required to complete every year. Most financial transactions and important life events will be entered into your tax return so that you can calculate exactly how much income tax you owe to the federal government.

Typically, you pay some amount of income tax through withholdings (see What is: Withholding) throughout the year, but your withholding amounts are only estimates. After you complete your tax return, you’ll find out how close the total withholding is to your actual tax owed.