A memory card is an electronic data storage device used for storing digital information, typically using flash memory. These are commonly used in digital portable electronic devices. They allow adding memory to such devices using a card in a socket instead of a protruding USB flash drives.
The basis for memory card technology is flash memory. It was invented by Fujio Masuoka at Toshiba in 1980 and commercialized by Toshiba in 1987.
PC Cards (PCMCIA) were the first commercial memory card formats (type I cards) to come out, but are now mainly used in industrial applications and to connect I/O devices such as modems. In 1992, SanDisk introduced FlashDisk, a PCMCIA card and one of the first memory cards that did not require battery power to retain its contents. Since 1994, a number of memory card formats smaller than the PC Card arrived. The first one was CompactFlash and later SmartMedia and Miniature Card. The desire for smaller cards for cell-phones, PDAs, and compact digital cameras drove a trend that left the previous generation of "compact" cards looking big. In 2001, SM alone captured 50% of the digital camera market and CF had captured the professional digital camera market. By 2005 however, SD/MMC had nearly taken over SmartMedia's spot, though not to the same level and with stiff competition coming from Memory Stick variants, as well as CompactFlash. In industrial and embedded fields, even the venerable PC card (PCMCIA) memory cards still manage to maintain a niche, while in mobile phones and PDAs, the memory card has become smaller.
Initially memory cards were expensive, costing US$3 per megabyte of capacity in 2001; this led to the development of miniaturized rotating magnetic disk memory devices such as the Microdrive, PocketZip and Dataplay. All three concepts became obsolete once flash memory prices became lower and their capacities became higher by 2006.
Since 2010, new products of Sony (previously only using Memory Stick) and Olympus (previously only using XD-Card) have been offered with an additional SD-Card slot.