title: What's the meaning of Base SDK, iOS deployment target, Target, and Project in xcode
body: <p>Say I set base SDK to 7, what does it mean? It could mean that the app would run on iOS 7. But that's what iOS deployment target is for.</p>
  
  <p>Also why do I specify those 3 values in both project and target. It doesn't make sense. Why specify the same thing twice?</p>