title: Close only one window in Emacs
body: <p>In vim, buffer can be split horizontally or vertically by <code>:sp</code> or <code>:vsp</code>. And a buffer can be closed by <code>:q</code>.</p>
  
  <p>Likewise in emacs, window can be split horizontally by <code>C-x 2</code>, and vertically by <code>C-x 3</code>.
  And close all other window by <code>C-x 1</code>.</p>
  
  <p>But, how can I close only one window, like <code>:q</code> in vim?</p>