Android
Android is an open source mobile operating system developed by Google and based on the Linux kernel. Android was developed primarily for touch screen devices, such as smartphones and tablets, although there are specialist versions for Android Wear (wrist watches) and Android TV.
Unlike the mobile operating system iOS, Android is not exclusively used with the hardware from one manufacturer. Due to its open source nature, manufacturers can, and in the majority of cases do, customise Android to meet the needs of their specific devices. Regardless of whether a manufacturer customises Android, all Android based devices have access to the Google Play store, where there are in excess of a million apps available for download.
Android File System
The Android file system consists of six main partitions, 'boot', 'system', 'recovery', 'data', 'cache', and 'misc'. To handle external storage, there are two further partitions, 'sdcard' and 'sd-ext'. Due to the ease of customisation of Android, there may be additional partitions depending on the make and model. Below is an outline of these partitions, along with some of their subdivisions.
/ ├── boot/ ← Android kernel plus other items needed to boot the device. ├── system/ ← Android OS system files. │ ├── bin/ ← System binaries. │ ├── lib/ ← Shared libraries. │ └── framework/ ← Java framework .jar files. ├── recovery/ ← Allows device to boot in recovery mode by utilising a backup. ├── data/ ← Main user data partition. │ ├── app/ ← Installed APKs. │ ├── data/ ← App private data. │ ├── misc/ ← Miscellaneous system info (e.g., WiFi configs). │ ├── media/ ← Encrypted storage mount point. │ └── system/ ← User accounts, settings ├── cache/ ← Frequently accessed app data and components. ├── misc/ ← Contains miscellaneous system settings. ├── sdcard/ ← External storage for user files, photos, downloads. └── sd-ext/ ← Additional partition of the sdcard partition, not always present.