Google ANDROID 2.3.4 - Manual (Page 49)

Android basics 49
AUG-2.3.4-105 Android User’s Guide
Managing how applications use memory
As described in “Opening and switching applications” on page 41, you typically don’t
need to worry about managing applications beyond installing, opening, and using
them. The operating system manages how they use memory and other resources
automatically. But there are times when you may want to know more about how
applications are using the memory and other resources in your phone.
Applications use two kinds of memory in your phone: storage memory and RAM.
Applications use storage memory for themselves and any files, settings, and other
data they use. They also use RAM (memory that is designed for temporary storage
and fast access) when they are running.
All phones have internal storage. This is the memory where most applications and
many kinds of files and data for those applications are stored. The operating system
manages and carefully guards internal storage, because it can contain your private
information; you can’t view its contents when you connect the phone to a computer
with a USB cable.
Depending on your model of phone, your phone also has either internal USB storage
or a removable SD card. This is the memory whose contents you can view and copy
files to and from when you connect your phone to a computer (as described in
“Connecting to a computer via USB” on page 67). Some applications are also
designed to be stored in this memory, rather than in internal memory, by default or as
an option.
The operating system also manages how applications use your phone’s RAM. It only
allows applications and their component processes and services to use RAM when
they need it. It may cache processes that you’ve been using recently in RAM, so they
restart more quickly when you open them again, but it will erase the cache if it needs
the RAM for new activities.