You will receive a 1099-B(Proceeds From Broker and Barter Exchange Transactions) if you sold any stocks this year. You will input the information on your 1099-B into the system which will create Form 8949 for the IRS.
They are not the same thing, but they are complements of each other(If you receive a 1099-B you file Form 8949).
You can select this link for more information: When to Use IRS Form 8949 for Stock Sales
To enter Form 1099-B:
1. Go to "Federal Taxes"
2. Choose "Wages and Income"
3. Select "I'll choose what I work on"
4. Scroll down to "Investment Income", select "show more"
5. Select "Stocks, Mutual Funds, Bonds, Other"
6. When asked "Did you sell any investments in 2016?", answer "Yes"
7.Continue through the interview questions until you arrive at the screen that says "Let Us Enter Your 1099-B"
8. After entering the information from your 1099-B, Click on "I'll enter additional info on my own" (see attached screenshot)
9. On the next screen you will be able to enter Box 4 Federal tax withheld
