Readonly memory (ROM) is a type of computer memory that is read-only, meaning that it cannot be modified after it has been programmed. There are several synonyms for the term "readonly memory" that are commonly used in the field of computer science, including "read-only storage" (ROS), "permanent memory," and "non-volatile memory." These terms all refer to memory that is designed to be read-only and cannot be altered, ensuring that the data stored within it remains consistent and unchangeable. ROM is often used to store the firmware code for electronic devices, including video game consoles, routers, and network switches.