The Full form of SD is Secure Digital. Secure Digital (SD) Card is a non-volatile memory card format. SD card is developed by the SD Card Association (SDA) for use in portable devices and popular storage media like mobile devices and digital cameras. In August 1999, a standard was introduced by joint efforts between SanDisk, Panasonic (Matsushita Electric) and Toshiba as an improvement over Multi Media Cards (MMC) and has become the industry standard. The three companies formed SD-3C, LLC, a company that licenses and enforces intellectual property rights associated with SD memory cards and SD host and ancillary products. To promote and create SD Card standards, the companies also formed the SD Association (SDA), a non-profit organization, in January 2000. Now, SDA has about 1,000 member companies. Secure Digital includes five card families available in three different sizes. The five families are the original Standard-Capacity (SDSC), the High-Capacity (SDHC), the extended-Capacity (SDXC), the Ultra-Capacity (SDUC) and the SDIO, which combines input/output functions with data storage.