Aside from both starting with W, they are completely different. The IRS has a serious lack of imagination when numbering forms.W-9 is the for a contractor gives to the company paying them. It just has their name, address, and tax ID so the has the information for the accounts payable department to send them a 1099 at the end of the year (usually a 1099-MISC).W-2 is the form an employee receives from their employer at the end of the year with the employees total earnings, withholdings, and other tax information the employe needs to do their personal tax return.The W-9 a contractor fills out is more similar to a W-4 that an employee fills out with their name, address, SSN, etc.The W-2 the employee receives at the end of the year is more similar to the 1099 a contractor receives showing the total amount they were paid for the year.