title: Vulkan command execution order
body: <p>Quoting Vulkan 1.0 specification document, chapter.5(Command Buffers) 4th paragraph, </p>
  
  <p>"Unless otherwise specified, and without explicit synchronization, the various commands submitted to a queue via command buffers may execute in arbitrary order relative to each other, and/or concurrently"</p>
  
  <p>In 1st paragraph of chapter 2.1.1(Queue Operation), it also states</p>
  
  <p>"... Command buffers submitted to a single queue are played back in the order they were submitted, and commands within each buffer are played back in the order they were recorded"</p>
  
  <p>Does "arbitrary order" in chapter 5 mean even out-of-order? Then isn't it a conflict to statement of chapter 2.1.1 "played back in the order they were submitted"? Or are commands just "PLAYED BACK" in-order but "EXECUTED" out-of-order? </p>