title: PYTHONPATH on Linux
body: <p>I'm novice in this, and I have started learning Python, but I have some questions that I'm not be able to understand,</p>
  
  <ol>
  <li>What exactly is the PYTHONPATH (on Ubuntu)? Is it a folder?</li>
  <li>Is Python provided by default on Ubuntu, or does it have to be installed explicitly?</li>
  <li>Where is the folder in which all modules are (I have a lot folders called <code>python_</code>)?</li>
  <li>If I wish a new module to work when I'm programming (such as pyopengl) where should I go to introduce all the folders I've got in the folder downloaded?</li>
  <li>Coming back from the PYTHONPATH issue, how do I configure the PYTHONPATH in order to start working on my new module?</li>
  </ol>