SD card or the Secure Digital card is a memory card that is non-volatile in nature
. SD cards find their application in several portable devices such as PDAs, mobile phones, Digital cameras, Media players, video games, GPS devices and camcorders. SD cards are primarily manufactures by the famous giants in the electronics industry like SanDisk, Toshiba and Panasonic.
Though based on the multi media cards, SD cards differ from them in various features. SD cards are given asymmetric shape unlike the media card. This is done in order to prevent the SD card from being inserted vertically or upside down. SD cards are thick. Their standard size being 32mm x 24mm x 2.1mm. There are thinner versions of SD cards available which are the miniSD or microSD. SD cards are provided with electrical contacts which are placed beneath the card"s surface. This would protect the card (the electrical contact area) from contact with the user"s fingers. Secure Digital cards are enabled with a data transfer rate of 10-20MB/s. This range keeps changing as new technologies evolve.
SD cards are advantageous in the sense that they can be used in PC card or Compactflash slots with an active electronic adapter. Special SD cards come along with a USB connector which will make them compatible with desktop and laptop computers. SD cards can be accessed through connectivity ports like FirmWire, USB and Parallel printer port by using card readers. Using a FlashPath adapter allows SD cards to be accessed through a floppy drive.
SD cards are generally preformatted with FAT 32 File system or FAT system which is on top of an MBR partition scheme. This file system is ubiquitous and hence any host device with an SD reader can be used to access the card. A corrupted data can be retrieved or repaired with help of the utilities available in the standard FAT.