title: What is the difference between a Process' pid, ppid, uid, euid, gid and egid?
body: <p><em>Context: I'm getting the current Ruby process ID.</em></p>
  
  
  
  <pre><code>Process.pid  #=&gt; 95291
  
  Process.ppid #=&gt; 95201
  
  Process.uid  #=&gt; 501
  
  Process.gid  #=&gt; 20
  
  Process.euid #=&gt; 501
  
  Process.egid #=&gt; 20
  </code></pre>