The command line houses the main content in the Internet Explorer 9 web browser. The three icon lines found in IE 8 were reduced to a single command bar in IE 9. The UI went from chaotic to minimalistic. IE8 had a cluttered user interface, which the IE9 update fixed.
Internet Explorer 9 was a monumental upgrade from Internet Explorer 8 and the versions that came before that: Internet Explorer 7, Internet Explorer 6, etc.
