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Two other settings available from the Menu icon can have dramatic
effects, but may sometimes be useful:
Data roaming can result in steep additional charges. However,
in some locations this may be the only way to connect to the
Internet.
Restrict background data affects all your apps across all
available networks, and may cause some features to stop
working. This is an extreme step that should be used with
caution.
Optimize memory usage
You typically don't need to worry about managing apps beyond
installing, opening, and using them. But there may be times when
you want to know more about what's happening behind the scenes.
Apps use two kinds of memory: internal storage and RAM. They use
internal storage for themselves and any files, settings, and other
data they use. They also use RAM (memory designed for temporary
storage and fast access) when they're running.
Android manages and carefully guards the portion of internal
storage where the system, apps, and most data for those apps are
stored, because this area may contain your private information. It's
not possible to view this portion of internal storage when you
connect your device to a computer with a USB cable. The other
portion of internal storage, where music, downloaded files, and so
on are stored, remains visible for your convenience.
Android also manages how apps use RAM. It may cache some
things you've been using recently, for quicker access if you need
them again, but it will erase the cache if it needs the RAM for new
