jQuery mobile css files

jQuery mobile css files

Hi,
I'm new to jQuery mobile and a little bit confused by all the css files provided :

  1.  jquery.mobile-1.4.1.min.css
  2.  jquery.mobile.external-png-1.4.1.min.css
  3.  jquery.mobile.icons-1.4.1.min.css
  4.  jquery.mobile.inline-png-1.4.1.min.css
  5.  jquery.mobile.inline-svg-1.4.1.min.css
  6.  jquery.mobile.structure-1.4.1.min.css
  7.  jquery.mobile.theme-1.4.1.min.css

when to use them ? and in what order they should be used ?

Thanks