title: Getting "file exists" error when trying to create a directory (mkdir)
body: <p>I'm very new at command line and am having a problem with creating basic directories.</p>
  
  <p>I want to create a directory (let's call it "Blue") inside my documents folder. I am in my Home directory (where my documents folder lives) and expected the following command to do what I wanted</p>
  
  <p>mkdir Blue Documents</p>
  
  <p>However, I get an error message that says "mkdir: Documents: File Exists" and my "Blue" directory is just created under my Home directory.</p>
  
  <p>How should I alter my command to specify that I want the "Blue" directory created under my Documents directory? I am using Terminal on OS X </p>