How to make site load smoothly

I have a php website that loads pretty fast, but it won't load smoothly like most other sites. For example, every time you go to a page on my site, it's like the pages and the elements are refreshing.

In other sites like reddit.com, their page loads very smoothly. The header and sidebar stay very still when loading another page there.

How do I make my site load smoothly, like just make it so the header and/or sidebar stay still and not look like it's refreshing when loading another page there.

Updates: this mostly happens in firefox. It could be just the browsers or it could be just my site. But other sites seems to load smoothly as described above in Firefox. My site does not.

 

I think the solution is called Ajax. That would make it possible. Ajax was designed for such tasks.

 

Hi , maybe your hosting company bandwidth , server resources are not good. Do you want to post URL for test? You could also use http://tools.pingdom.com/fpt/ to see if any recommendations.

Lord_stone is perfectly correct also in that dymanic sites use Ajax sometimes to pull back data without having to visit another page. Looks great.

However I get the feeling your issue isnt even related to data but more your graphic elements loading slowly...