title: Are Elixir variables really immutable?
body: <p>In Dave Thomas's book Programming Elixir he states "Elixir enforces immutable data" and goes on to say: </p>
  
  <blockquote>
    <p>In Elixir, once a variable references a list such as [1,2,3], you know it will always reference those same values (until you rebind the variable).</p>
  </blockquote>
  
  <p>This sounds like "it won't ever change unless you change it" so I'm confused as to what the difference between mutability and rebinding is. An example highlighting the differences would be really helpful. </p>