A Level Computer Science OCR Practice Exam

Read Only Memory (ROM) is non-volatile and is fixed during manufacturing, making it the correct choice in this context. Non-volatile memory retains its contents even when the power is turned off, which is a key characteristic of ROM. This type of memory is typically used for firmware or the basic instructions needed to boot up a computer or other devices, which are written during the manufacturing process and cannot be easily modified or erased.

In contrast, Random Access Memory (RAM) is volatile, meaning it loses its contents when power is lost, and it is frequently used for temporary data storage while a computer is operational. Virtual Memory is not a physical memory type; rather, it's a technique that uses a portion of the hard drive to extend the apparent amount of RAM available. Cache Memory, while also volatile, is designed to provide faster access to frequently used data but is not fixed in the same way that ROM is.