SDHC (Secure Digital High Capacity) is an extension of the SD cards, but as the name suggest, is higher capacity. SDHC memory cards come in a variety of 3 classes, all based on their transfer rates. For example, Class 6 SDHC memory cards transfer files at 6 MB per seconds. SDHC cards also have a higher capacity versus regular SD cards. SDHC-enabled products are backward compatible with SD memory cards. Your data written on SDHC cards is protected, even if you insert your SDHC in a device that isn't compatible. SDHC cards also work in standard SD slots with a firmware upgrade.
