The W-2 form is a wage and tax statement that your employer sends to you and the IRS at the end of the year. It reports your annual wages and the amount of taxes withheld from your paycheck. The W-4 form, on the other hand, is filled out by you and given to your employer to determine the amount of taxes to withhold from your paycheck. Essentially, the W-2 reports what happened in the past year, while the W-4 helps project and manage your tax withholding for the current year.