a. write memory
This can also be abbreviated to just 'write' or 'wr'. Write erase
Removes any configuration in NVRAM. Write Term shows you the configura-
tion currently being used by the box - this may not be the same as
the config in NVRAM (show config) if changes have been made since the
last 'write mem' was performed. The other two will result in parser
error messages.
Reference: Cisco Router Command Reference.