title: What is the difference between include and require in Ruby?
body: <p>My question is similar to "<a href="https://stackoverflow.com/questions/156362/what-is-the-difference-between-include-and-extend-in-ruby">What is the difference between include and extend in Ruby?</a>".</p>
  
  <p>What's the difference between <code>require</code> and <code>include</code> in Ruby?  If I just want to use the methods from a module in my class, should I <code>require</code> it or <code>include</code> it?</p>