title: What is Java Byte Array and How should it be used?
body: <p>What does it mean by byte array ? I mean it holds the 0s and 1s just like how data is hold in memory ? </p>
  
  <p>For example </p>
  
  <pre><code>String a = "32";
  byte [] arr = a.getBytes() ; 
  </code></pre>
  
  <p>What does exist now inside arr array,why and when to use it? </p>