ruu
RUU is an acronym that can refer to several terms, most commonly to ROM Update Utility in mobile technology. ROM Update Utility refers to a Windows-based tool used to flash official ROM packages onto certain smartphones, particularly HTC devices. The tool communicates with the phone when it is in bootloader or HBOOT mode and applies a ROM package that contains the operating system and firmware for a specific model and regional variant. RUUs are used to install official updates, restore devices, or unbrick after software problems. Because they flash low-level firmware, RUUs require the correct ROM package for the device; using an incompatible package can render the device unusable.
History and scope: The RUU workflow was prominent in the Android era for HTC devices before OTA
Other uses: As an acronym, RUU can refer to terms outside mobile firmware, depending on the context.