title: How to replace a word in Emacs?
body: <p>Given the following sentence:</p>
  
  <blockquote>
    <p>This is one two three.</p>
  </blockquote>
  
  <p>When I move the cursor to the space between <strong>one</strong> and <strong>two</strong>, I would like to replace <strong>two</strong> with XXX.
  I know there is a way in vi so that I can mark <strong>two</strong> as the modified string so that when I finish entering the new string and the new string replaces the <strong>two</strong> in-place.</p>
  
  <p>// Update-1 //</p>
  
  <p>The corresponding command in vi is 'cw'</p>