Micro SD card is a format for removable flash memory cards. Micro SD card is about a quarter of the size of an SD card and is the newest standard of SD flash memory. There are adapters which allow a Micro SD card to be used in devices intended for SD, miniSD, or MemoryStick Duo cards. However, they are not universally compatible.
Micro SD card is derived from SanDisk TransFlash and is used mainly in mobile telephones, but also in handheld GPS devices, portable audio players, video game consoles and expandable USB flash memory drives.
Micro SD cards and TransFlash are the same (each can be used in devices made for the other), except that Micro SD adds support for SDIO mode, enabling non-memory cards like Bluetooth, GPS, and Near Field Communication devices.
Micro SD card is ideal for use in storing media-rich files such as music, videos, and photographs in compatible mobile phones. Micro SD cards are available in capacities from 64MB to 8GB. Micro SD Cards of 4GB and larger are only available in the newer SDHC format.