What type of programming is characterized as unchangeable?

Firmware is indeed characterized as unchangeable because it is a specialized type of software that is closely tied to hardware. It provides the low-level control for a device's specific hardware and is often embedded directly into the device. The nature of firmware means that it is typically not intended to be altered or updated frequently, contrasting with other types of software that can be easily modified or replaced.

Firmware resides in non-volatile memory (such as ROM or flash memory), which is not designed for frequent writing and rewriting. Because of this, firmware updates can be more complex and less common than updates for application software or open-source projects, which are intended to be modified and distributed widely. This makes firmware a stable and reliable component of the hardware it supports, ensuring that the core functionalities of devices such as routers, embedded systems, and various electronic appliances remain consistently operational without user intervention.