title: Defining STA: "single thread affinity" or "single threaded apartment"; and how they relate
body: <p>I'm working with WPF and am reading through materials on STA.  Two questions:</p>
  
  <p>1) STA is defined as standing for both "single thread affinity" and "single threaded apartment" by different articles.
  This says the former:
  <a href="https://msdn.microsoft.com/en-us/library/ms750441(v=vs.110).aspx" rel="noreferrer">https://msdn.microsoft.com/en-us/library/ms750441(v=vs.110).aspx</a>
  This says the latter:
  <a href="https://msdn.microsoft.com/en-us/library/ms742522(v=vs.110).aspx" rel="noreferrer">https://msdn.microsoft.com/en-us/library/ms742522(v=vs.110).aspx</a></p>
  
  <p>Which is it, or can STA refer to either of these related concepts?</p>
  
  <p>2) Is it correct to describe their relationship as:
  Single threaded apartment is a model used by various components of Windows, thread affinity is a characteristic of that model?</p>
  
  <p>Thanks.</p>