What is the use of ROM in microcontrollers?

ROM (Read-Only Memory) in microcontrollers is used to store firmware and essential programs that are critical for the device's operation. This non-volatile memory retains data even when power is lost, ensuring that the microcontroller can boot up and function correctly after being powered off. Additionally, ROM provides a stable environment for the execution of instructions, as its contents cannot be altered during normal operation, enhancing security and reliability in embedded systems.