A memory card, flash card or memory cartridge is an electronic flash memory data storage device used for storing digital information. If you want to increase your phone's memory or invest in small, secure backup storage, a micro SD card shall be ideal. However, you need to be careful while removing your memory card, and ideally you'll only have to remove it while changing phone. An SD Card (Secure Digital Card) is an ultra small flash memory card designed to provide high-capacity memory in a small size. SD cards are used in many small portable devices such as digital video camcorders, digital cameras, handheld computers, audio players and mobile phones.