title: What does a C++ program require to run?
body: <p>This question has been bothering me for a while now. Let's consider the two following programs:</p>
  
  <pre><code>#incude &lt;iostream&gt;
  int main()
  {
     std::cout &lt;&lt; "Hello, World!";
  }
  </code></pre>
  
  <p>and</p>
  
  <pre><code>int main()
  {
     int x = 5;
     int y = x*x;
  }
  </code></pre>
  
  <ol>
  <li>Windows:
  The first example, naturally, requires some system .dll's for the console. I understand that. What about the second? Does it need anything to run? Some runtime libraries? By the way, what do runtime libraries actually do?</li>
  <li>Linux:
  No idea, can you enlighten me?</li>
  </ol>
  
  <p>I know it depends on the compiler and OS, but I need either a general answer or particular examples. TIA.</p>