miniSD is a type of removable flash memory card. Like any flash memory card, it can be used to store various types of files, including photos, videos, music, or software.
There are adapter cards that allow a miniSD card to be used in an SD card slot. This is a convenient way to use a miniSD card with a card reader on a PC, to transfer files between a PC and a phone.
As the name implies, miniSD is similar to the SD format, but smaller.
miniSD is smaller than MMC and SD, but larger than TransFlash, which is also called microSD.
miniSD is close in size to the competing RS-MMC format.