title: difference between tab ,space and blank in C
body: <p>I came across the following code in Ritchie and kernighan C,for counting no. of words ..</p>
  
  <pre><code>#include&lt;stdio.h&gt;
  #define IN 1
  #define OUT 0
  main()
  {
      int c,n1,nw,nc,state;
      state = OUT;
      n1 =nw = nc = 0;
      while((c = getchar())!=EOF)
      {
          ++nc;
          if(c == '\n')
              ++n1;
          if(c == ' '||c == '\n' ||c == '\t')
              state = OUT;
          else if(state == OUT)
          {
              state = IN;
              ++nw;
          }
      }
  
      printf("%d %d %d\n",n1,nw,nc);
  }
  </code></pre>
  
  <p>I guess here <code>c == ' '</code> and <code>c == '\t'</code> are doing the same job. </p>
  
  <p>Can someone explain me difference between tab, space, whitespace, blank, form feed and vertical tab?</p>