Traditionally, web applications used sessions to maintain state while the user navigated the interface, with full page reloads for every screen (typically visib

Traditionally, web applications used sessions to maintain state while the user navigated the interface, with full page reloads for every screen (typically visible as a blank white page as the next screen loads from scratch). By contrast, single-page application (SPA) architecture holds session state in a long running in-browser Javascript application. This style is particularly strong when user actions only need to modify a portion of the screen.