Non-volatile memory, nonvolatile memory, NVM or non-volatile storage is computer memory that can retrieve stored information even after having been power cycled (turned off and back on). Examples of non-volatile memory include read-only memory, flash memory, ferroelectric RAM (F-RAM), most types of magnetic computer storage devices (e.g. hard disk drives, floppy disks, and magnetic tape), optical discs, and early computer storage methods such as paper tape and punched cards.