title: Difference between sh and Bash
body: <p>When writing shell programs, we often use <code>/bin/sh</code> and <code>/bin/bash</code>. I usually use <code>bash</code>, but I don't know what's the difference between them.</p>
  <p>What's main difference between Bash and <code>sh</code>?</p>
  <p>What do we need to be aware of when programming in Bash and <code>sh</code>?</p>