The permanent holding place for digital data, until purposely erased. Storage is a repository that retains its content without power and includes magnetic disks, solid state drives (SSDs) and flash drives. The chips in these devices are said to be "non-volatile." Rewritable CD, DVD and Blu-ray discs, as well as magnetic tapes, are also non-volatile storage.
Storage specifically excludes the computer's main memory. Main memory, comprised of DRAM and SRAM chips, is a temporary workspace for executing instructions and processing data. These RAM chips do not hold their content when the power is turned off. Memory chips are "volatile."
Storage Vs. Memory - More Confusing All the Time
Over the years, some vendors referred to disks and tapes as "memory" products, which blurs the distinction between storage and memory (RAM). To further confuse things, the flash "memory" chips in memory cards, solid state drives (SSDs) and USB drives are, in fact, storage chips that hold their content without power. See storage vs. memory
, dynamic RAM
and static RAM
. For summaries of all storage technologies, see magnetic disk
, magnetic tape
and optical disc
They're All Chips, But...
The RAM chips (top) and the storage chips (bottom) in a USB drive and CompactFlash card (cases are removed) may look alike, but RAM chips are fast and volatile, while storage chips are slower and non-volatile. See memory module
, USB drive
In the early 1990s, this 670MB multi-platter hard drive weighed 17 pounds including its case. By 2006, a half-ounce Microdrive (center) had 12 times as much storage on a single platter the size of a quarter. The solid state microSD card (right) weighs half a gram. See hard disk