A W-2 form is a tax document that employers in the United States must provide to their employees at the end of each year. It reports the employee's annual wages and the amount of taxes withheld from their paychecks. This form is essential for employees when filing their income tax returns. The W-2 form includes information such as the employee's Social Security number, the employer's identification number, and details about state and federal taxes. Employees use this information to ensure they accurately report their earnings and pay any taxes owed or claim refunds.