(To view a larger image with more detailed description tap or click its thumbnail.)
Although multitasking is one of the best new features of IOS version 4.2 on the iPad & iPhone, not many beginning users are aware of how it can be used, let alone how to begin using it.
Multitasking is invoked by double clicking the Home button on the surface of the iPad/iPhone. In older versions of IOS, double clicking the button would return one to the first page of the Home screen. Since icon groups AKA categories was also a new feature introduced with the newest IOS version, there is no longer much need to scroll through page upon page of application icons.
Double clicking the Home button slides the current home page up and shows the list of currently running applications in the background.
Take for example, the normal routine of switching from Pages to Photos: Click of the Home button, opening Pages, performing an editing task, click the Home button again, find Photos app, copy a photo, click home button re-open pages, ad nauseum. The multitask double-click way is much faster, and most important returns to the application as you left it. This is best illustrated when switching back and forth from Safari, and helps eliminate many instances of the maddening page reload behaviour.
A picture says a thousand words: Start with the first image in the screenshots above to view a real world example of multitasking.