Acer S510 - Manual (Page 19)

19
Multitasking
You can have multiple applications open at the same time. To
open a new application, tap the home button to return to the
Home screen, then start the new application.
Tip: To prolong battery life, it is better to close an application when you’ve
finished using it. Do this by either pressing the Back key or the Menu button and
selecting Exit (if available).