Yes, this letter is a request from the IRS for more information in order to process your tax return. The letter should say what's needed, but they are usually hard to understand.
If you purchased Audit Defense for the return, follow this link to get help with your letter.
If you didn't purchase Audit Defense, you can contact the Audit Support Center for help with your letter. Follow this link for more. Either option can help you understand exactly what to do next.