ROM is an example of non-volatile memory.
Types of memory that retain their contents when power is turned off. ROM is nonvolatile, whereas RAM is volatile. This term often refers to the CMOS memory in PCs that holds the BIOS.
RAM is referred to as volatile memory and is lost when the power is turned off whereas ROM in non volatile and the contents are retained even after the power is switched off. RAM is called volatile because it is temporary memory. ROM is called non volatile because it is permanent memory.
ROM that is read only memory is non volatile because all the data in it doesn't get erased after shutting down the computer and restarting it. Whereas RAM that is random access memory is volatile because all the data in it gets erased after shutting down the computer and restarting it.
non-volatile memory include read-only memory (see ROM), flash memory, most types of magnetic computer storage devices (e.g. hard disks, floppy discs and magnetic tape), optical discs, and early computer storage methods such as paper tape and punched cards.