Look at both W-2s closely to see if one of them is marked 'corrected'. There is a box that would be checked at the top of the page to indicate it is a corrected W-2.
If it is, then use the numbers reported on the corrected form and not the other one. You will only enter a single W-2 when one is corrected. Also, after you enter the corrected W-2 in TurboTax, be sure to indicate it is corrected by checking the box in the follow-up question when you've entered all the data.
There are a couple of other situations where you might receive two W-2s from the same employer described in the TurboTax article below. If your situation does not fit any of these, you should contact your employer for more information about why you received two forms.
How do I handle multiple W-2s from the same employer?