The term "speed pages" refers to web pages that load as fast as they possibly can.

The basic idea behind speed pages is simple: Anything that can limit actual transfer time as well as speed up the users experienced waiting time (not necessarily the pages actual loading time) should be implemented.

These things are accomplished by simple yet extensive use of:

HTML
Write HTML so the browser can display content before all elements are loaded.

CSS
Keep style elements in external style sheets so they can be cached on the visitor's local machine.

JAVASCRIPT
Keep reusable codepieces in external javascript files so they can be cahed on the visitor's local machine.

From : echoecho.com