SD, or "Secure Digital," cards are portable flash memory devices. Since their release in 2000, SD cards have become the most popular flash memory card format. The cards come in numerous physical and storage sizes. However, the format does have some compatibility issues.
History
In 1999, SanDisk, Toshiba and Matsushita announced a new memory card format to compete with Memory Stick, manufactured by Sony. The first SD cards were released in 2000. A new format, SDHC, which has a larger capacity, was introduced in June 2006.
Size
SD cards come in three physical sizes. SD cards are the largest. MiniSD cards are slightly smaller than SD cards. MicroSD cards are the smallest of the three.
Formats
SDHC is the largest current format, with a 32-gigabyte limit. A new SD format will be introduced in the near future and increase the maximum storage size to 2 terabytes.
Popularity
SD had emerged as the most popular memory card format because of its wide acceptance. With the exception of Sony, Fujifilm and Olympus, almost every major electronics manufacturer uses it in their products.
Issues
SDHD is not backwards compatible with older formats. As a result, older electronics devices cannot use larger SD formats.
Tags: card format, memory card format, cards come, flash memory, memory card, most popular