title: Difference between map, applymap and apply methods in Pandas
body: <p>Can you tell me when to use these vectorization methods with basic examples? </p>
  
  <p>I see that <code>map</code> is a <code>Series</code> method whereas the rest are <code>DataFrame</code> methods. I got confused about <code>apply</code> and <code>applymap</code> methods though. Why do we have two methods for applying a function to a DataFrame? Again, simple examples which illustrate the usage would be great!</p>