title: What is a Git commit ID?
body: <p>How are the Git commit IDs generated to uniquely identify the commits?</p>
  
  <p>Example: <code>521747298a3790fde1710f3aa2d03b55020575aa</code></p>
  
  <p>How does it work? Are they only unique for each project? Or for the Git repositories globally?</p>