Different memories that are used in CISCO router include :
NVRAM (Non-volatile RAM) : It is used to store startup configuration files. It also retains its content even after a device is restarted or powered down.
DRAM (Dynamic Random-Access Memory) : It is used to store configuration files that are being executed. It loses its content when a device is restarted.
ROM (Read Only Memory) : It is used to store a bootstrap program that initializes a boot process. It also runs and maintains instructions for POST diagnostics.
Flash Memory : It is used to store CISCO IOS. It can also be used to store other files such as backup configuration files.
