Android ROM

Android ROM

(Android Read Only Memory) A file containing the executable instructions (a system image) of an Android OS and affiliated apps. The "stock ROM" comes installed on the phone or tablet, while a "custom ROM" comes from a third party. The custom ROM is either a uniquely modified OS, such as Cyanogen, or a stock version made available for older devices or for new devices before the vendor release date. See CyanogenMod.

Flashing the ROM
Flashing a ROM means installing the system image into the device's internal flash memory. Flash memory holds the Android's firmware, the same as most other portable devices with an embedded OS.

Change the Meaning Altogether
A ROM is a read-only-memory chip that provides unalterable storage of programs and data. However, an Android ROM is entirely replaceable. See ROM, Android recovery image and Android rooting.