The form that an employer must send to an employee and the IRS at the end of the year. The W-2 form reports an employee's annual wages and the amount of taxes withheld from his or her paycheck. A W-4 is a form that individuals complete for withholding purposes, whereas a W-2 form is for employers to fill out. The employer must provide the employee their W-2 form by the deadline set by the IRS.