title: In Xcode project target build settings, What is Mach-O Type?
body: <p>After getting tired of numerous Match-O linker error, I want to know that this thing means. Instead of trial and error solution, I would like to know the concept behind these things. Specifically I want to know the difference between :</p>
  
  <ol>
  <li>Executable</li>
  <li>Dynamic Library</li>
  <li>Bundle</li>
  <li>Static Library</li>
  <li>Relocatable Object File</li>
  </ol>
  
  <p>These are the options presented when I click on Mach-O Type settings on Linking section. Some small definition or some link to appropriate content is ok too. </p>