title: alloc and init what do they actually do
body: <p>Can someone explain to me what init and alloc do in Obj-C. I am reading this obj-c book that gives an example of creating object but it does not really go into details of what it does. What does alloc return? what does init return?</p>
  
  <pre><code>Animal * k = [Animal alloc];
  k = [k init];
  </code></pre>