As Android is based on the modified Linux kernel, its file structure resembles the one that can be found on various Linux distributions. The file hierarchy is a single tree, with the top of it called the root directory or root (generally specified with the / symbol), and multiple standard Linux directories, such as /proc, /sbin, and so on. The Android kernel is shipped with multiple supported filesystems; the exact selection varies depending on the version of the OS and the device's manufacturer. It has been using EXT4 as the default main filesystem since Android 2.3, but prior to that YAFFS was used. External storage and SD cards are usually formatted using FAT32 to maintain compatibility with Windows.
In terms of the specifics of the directory structure, the official Android documentation defines the following data storage options:
- Internal: On modern versions of Android, internal storage is mainly represented by the /data/data/ directory and its symlink /data/user...
