NVRAM

Non-Volatile Random Access Memory (NVRAM) is a computer memory chip which will not lose its information when the power is lost. It is mostly used in computer systems to store settings which must survive a power cycle (like number of disks and memory configuration).

The most well known example would be ferromagnetic memory used in the 1950s and '60s.

Today, the closest type of memory to NVRAM is Flash memory used in portable MP3 players. (it is really EEPROM, electrically erasable programmable read-only memory, but it can be rewritten thousands, sometimes million times.)

Currently, there are many types of NVRAM being developed for wide application based on various technologies, such as carbon nanotube technology, magnetic tunnel effect, Ovonic Unified Memory based on phase-change technology, and FeRAM ferromagnetic RAM.

NVRAM is also used in Routers It is used to provide storage for the startup configuration file