title: Internal tables declaration in ABAP
body: <p>I just started learning ABAP and I came acroos some different ways of declaring internal tables but I don't understand the difference between these ways. Which one is the best way?</p>
  
  <p><strong>Sample 1</strong></p>
  
  <pre><code>types: begin of ty_tab,
    field1,
    field 2,  
  end of ty_tab.
  
  data x_tab type ty_tab.
  data itab like standard table of x_Tab.
  </code></pre>
  
  <p><strong>Sample 2</strong></p>
  
  <pre><code>types: begin of ty_tab,
    field1,
    field2,
  end of ty_tab.
  
  types x_tab type standard table of ty_tab.
  data itab type x_tab.
  </code></pre>
  
  <p><strong>Sample 3</strong></p>
  
  <pre><code>data t_sflight type sflight.
  </code></pre>