Client-side and server-side page rendering modes in Page Bulider Theme

Client-side mode

In client-side mode the following applies:
• Page changes occur without a browser full page refresh. Upon a user request a SWITCH_PAGE client-side event is fired. This triggers the update of the page navigation, and the contents of the new page are loaded and replace the content of the prior page.
• Interaction with portlets and widgets updates only the affected portlet or widget, and possibly others as a result of wiring. Portlets are rendered as iWidgets by means of an iWidget Wrapper.
• The implementation and programming model for client-side mode is provided by the Mashups Enabler common component, and public builder events.

Server-side mode

In server-side mode the following applies:

• Page changes cause a browser full page refresh.
• Interactions with portlets result in a browser full page refresh.
• However, iWidgets are rendered and interact within the page just as in client-side mode. 

Theme adjustment  to Modes:
To render the portal theme, the same theme elements are used in both rendering modes. In general, you can write navigation iWidgets to fire a SWITCH_PAGE event. The internal JavaScript NavigationController of the theme determines the current rendering mode of the page and processes the event appropriately.