title: What does "source" create or activate the virtual env?
body: <p>I'm brand new to python, using terminal, pip and virtual env.
  From what I gather, the command 'source' activates the virtual environment and anything you do after that stays in the virtual environment like installing something with pip installs it only in your virtual environment.  However, do I need to actually create a folder or choose a location first before I run source?  In other words, does source create the virtual environment or only activate one that already exists?</p>
  
  <p>This stuff is really hard to wrap my head around.  I think one of the things that is hindering my development is that I'm not familiar with certain directory structures like bin, ect.</p>