The Rapid Ajax Paging block allows you load content from elsewhere on your site without having to reload the entire page.
On this page it is configured to load content within this page's #body element.
It works with standard links, which you can activate based on a css class, a css selector, or based on the link URL.
You can add multiple rules to a page if you'd like.
Each rule lets you specify the area that you want to load from the target page, and the element that the loaded content into. Typically you will load content from the "Main" area, and load it into some kind of #content or #body element, depending on your page's structure.
To try it out, click some of the links below (added by just using a standard page list block), or with the rapid paging links navigation on the right.