What type of memory is used to store fully functional Cisco IOS images in a switch?

Flash memory is utilized for storing fully functional Cisco IOS images in a switch. This type of memory is non-volatile, which means that it retains its contents even when the device is powered off. When a switch is powered on, it loads the IOS image from flash memory into RAM, where the operating system can be executed.

Flash memory is crucial for network devices because it allows for the storage of the IOS software, enabling upgrades and changes to the firmware without physically replacing the hardware. It also supports the ability to hold multiple versions of the IOS, which can be helpful in scenarios where version testing or rolling back to a previous version is necessary.

ROM, while containing the bootstrap program and basic diagnostics, does not hold the full IOS images. RAM is volatile memory used for running processes and temporarily holding data, while NVRAM is used primarily for storing configuration files and retains its data even without power.