title: What's the major importance of Abstraction?
body: <p>As a newbie in Java i would like to undestand some basic concepts , I'm on the Abstraction .. So i created this program to understand it 
  Here is my program : </p>
  
  <p><strong>First class (Parent class)</strong></p>
  
  <pre><code>public abstract class Myclass {
      int a = 10;
      int b = 20;
      abstract  void printvar();
  }
  </code></pre>
  
  <p><strong>Second class (child class)</strong></p>
  
  <pre><code>public class MySecondClass extends Myclass  {
      public void  printvar() {
          System.out.println("a = "+a +" b = "+b);
      }
      public static void main(String [] args) {
          MySecondClass inst = new MySecondClass();
          inst.printvar();
      }
  }
  </code></pre>
  
  <p>I created a class as  <strong><em>abstract</em></strong> (<strong>Myclass</strong>)  and  i declared my  <strong>abstract</strong>  function (to be defined in  the inherited class <strong>MySecondClass</strong>)
  I read that "<em>To achieve security - hide certain details and only show the important details of an object.</em>" so i imagine that i couldn't access to the class <strong>Myclass</strong> ...  So i can edit the function in the inherited class as i want to access some data (I knew the <em>private</em> keyword but without that) ! So no security if i can display other information using my abstract function :/ I misunderstand something ? Please help if so ;-)  .</p>