Restricted Stock Units (RSUs) vs Restricted Stock Awards (RS/RSA)

I have a 1099-B for the first time this year after selling stock that I received from my employer over the span of several years. It had a vesting period which had passed, but I don't understand if I should be marking the type as Restricted Stock Units or Restricted Stock Awards. Can you help me understand the difference between these and how to determine which one I have?