title: Compare Protocol in Swift vs Interface in Java
body: <p>I'm going through the iOS tutorial from <a href="https://developer.apple.com/library/prerelease/ios/referencelibrary/GettingStarted/DevelopiOSAppsSwift/Lesson1.html#//apple_ref/doc/uid/TP40015214-CH3-SW1" rel="noreferrer">Apple developer page</a>.</p>
  
  <p>It seems to me that <code>protocol</code> and <code>interface</code> almost have the same functionality.</p>
  
  <ul>
  <li><p>Are there any differences between the two?</p></li>
  <li><p>the different usage in the project?</p></li>
  </ul>
  
  <p><strong>Updated</strong> </p>
  
  <p><strong>Yes</strong>, I did read the link above and I'm still not sure what the differences and usage between <code>protocol</code> and <code>interface</code>. When I ask a question like this, I would like to see a simple explanation about the topic. Sometime it could be tough to get everything from the documentation.</p>