title: Difference between void and (int, string, etc.)
body: <p>Whats the difference between</p>
  
  <pre><code>public void Sum()
  </code></pre>
  
  <p>and</p>
  
  <pre><code>public int Sum()
  </code></pre>
  
  <p>I tried searching on Google/YouTube and I've learned that <code>public int Sum()</code> needs a <code>return</code> statement. I'm using <code>return</code> a lot, but I really dont know what is the use of it on methods.</p>