Managing how applications use memory

Managing how applications use memory

As described in “Opening and switching applications” on page 40, 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.