SD cards are commonly used as storage in electronics.
Many printers, cell phones, GPS units, MP3 players and other electronics utilize Secured Digital (SD) and Secured Digital High-Capacity (SDHC) cards. While they both utilize the same storage technology, SDHC is the successor to the SD format.
Physical Size
Both the standard SD card and SDHC cards share the same physical dimensions. They're 32 mm by 24 mm at 2.1 mm thick.
Storage Capacity
SDHC cards, as the name suggests, have a greater storage capacity than regular SD cards. SD cards can only hold up to 2 GB of data, whereas SDHC cards are capable of storing up to 32 GB.
Compatibility
SDHC cards are backwards compatible, meaning they can work in devices designed for SD cards. With a firmware upgrade to your device or card reader, it will read SDHC cards.
Sizes
MiniSD cards are smaller versions of the standard SD card. MicroSD cards are even smaller, still. Mini and Micro SDHC cards are also available. While physically smaller, they are have the same storage capacity as their larger counterparts. MiniSD cards require a device or card reader to have an actual MiniSD slot. MicroSD cards come with adapters, allowing them to fit into slots for normal SD/SDHC cards.
Tags: SDHC cards, card reader, device card, device card reader, MicroSD cards, MiniSD cards