Volatile memory is computer storage that only maintains its data while the device is powered. Most RAM (random access memory) used for primary storage in personal computers is volatile memory.
Volatile memory contrasts with nonvolatile memory, which does not lose content when power is lost. Non-volatile memory has a continuous source of power and does not need to have its memory content periodically refreshed. Examples of non-volatile memory include the hard disk, CD-ROM and storage devices like SATA or PCI express-based flash storage.