title: How is a program in a specific location?
body: <p>When writing a program, the program is sort of running in a particular directory which is the <em>current working directory.</em></p>
  
  <p>I'm trying to understand more about the idea of a cwd. How does a program know what its cwd is? Where is that information stored?</p>
  
  <p>I know perfectly well how to use the <code>os</code> module in python, but I don't really understand what it means to have a cwd. Is it simply a data attribute, "this is where we are", that we can change arbitrarily? And we simply look for things and create things on that particular section of the HD? Or is some sort of pathway actually opening and closing actively when we change cwd, like a door getting shut and another being opened?</p>
  
  <p>What <em>happens</em> on the computer when I change cwd in a program?</p>
  
  <p>This may be language-agnostic, I am unsure.</p>