title: When adding a README for git purposes, what does the keyword 'touch' do in the '$ touch README' command?
body: <p>I'm trying to understand the keyword <code>touch</code> used in adding a README to Github repo in Mac.</p>
  
  <pre><code>$ touch README
  </code></pre>
  
  <p>this adds a blank file titled <code>README</code>. So what does touch really represent?
  For example, in case of <code>$ subl README</code> - <code>subl</code> is going to launch sublime text.</p>