MicroSD (formerly known as TransFlash) is removable memory that’s starting to become common in mobile phones. It’s also used by some navigation systems for storing map data. Originally introduced by SanDisk in 2004, the format is much newer than secure digital or compact flash.
Because MicroSD memory doesn’t have any moving parts, it may be better than a hard drive in settings where rough motion and vibration are common (such as an off road vehicle or motorcycle).
MicroSD modules are physically about half the size of SD memory modules. Maximum capacity currently lags behind other formats.