title: What is this $PATH in Linux and how to modify it
body: <p>I have a few questions on this $PATH in Linux.</p>
  
  <p>I know it tells the shell which directories to search for executable files, so:</p>
  
  <ol>
  <li>What does it mean an environmental variable?</li>
  <li>How to change its path? and is it recommended to change it?</li>
  <li>IF i change it what are the consequences?</li>
  </ol>