title: What exactly is a connection in R?
body: <p>I've read through and successfully use <code>?connections</code> in R but I really don't understand what they are.</p>
  
  <p>I get that I can download a file, read and write a compressed file, ... (<em>that is I understand what the result of using a conection (open, do stuff, close) but I really don't understand what they actually do, why you have to open and close them and so on</em>).</p>
  
  <p>I'm hoping this will also help me understand how to more effectively use them (principally understand the mechanics of what is happening so I can effectively debug when something is not working).</p>