title: What is the use of begin in Scheme?
body: <p>I don't understand how using the <code>begin</code> keyword is useful in writing a sequence of expressions in Scheme. </p>
  
  <p>I mean, when I write expressions, aren't they supposed to be evaluated from left to right? So, why must I still include a <code>begin</code> keyword? </p>
  
  <p>I read that <code>begin</code> is supposed to eliminate side-effects from input and output. Can anyone give me a situation where begin is necessary?</p>