So, in order to make your Drupal site run quickly, it's essential to load those files as quickly as possible. It's easy to get started by enabling the aggregation and compression options in Drupal.
Aggregation gathers all the files together and loads them as one. Compression reduces the size of each individual file, stripping out unnecessary characters, whitespace and implementing CSS shortcuts.
In this video, Robert Ring shows you how to enable Drupal's core aggregation and compression options:
Note: in this video, Robert does have the Boost and Adminstration menu modules installed, so your site may look a little different. This video is part of "Speeding up Your Drupal Site" video class.